diff --git a/TODO.md b/TODO.md
index bd00fd7..a7827bd 100644
--- a/TODO.md
+++ b/TODO.md
@@ -4,7 +4,6 @@
 
 ## 测量
 
-- IPv6
 - 路由跳数、路径漂移和 trace
 - 握手耗时：TCP 连接耗时，TLS / QUIC 握手耗时（QUIC 目前没有真实握手积木）
 - 网页长截图
diff --git a/backend/agent/src/MoShiro.Agent/AgentApp.cs b/backend/agent/src/MoShiro.Agent/AgentApp.cs
index 70d72b6..814032b 100644
--- a/backend/agent/src/MoShiro.Agent/AgentApp.cs
+++ b/backend/agent/src/MoShiro.Agent/AgentApp.cs
@@ -15,6 +15,7 @@ public sealed class AgentApp : IDisposable
     public const string Version = MoShiro.Protocol.BuildInfo.Version;
 
     private readonly AgentConfig _config;
+    private readonly bool _ipv6Supported;
     private readonly LoadedNodeIdentity _identity;
     private readonly TimeProvider _time;
     private readonly INodeLog _log;
@@ -47,6 +48,12 @@ public sealed class AgentApp : IDisposable
         _uplink = new BackendUplink(time);
 
         IPAddress bind = IPAddress.Parse(config.Listen.Bind);
+        if (bind.Equals(IPAddress.IPv6Any) && !System.Net.Sockets.Socket.OSSupportsIPv6)
+        {
+            bind = IPAddress.Any;
+        }
+
+        _ipv6Supported = bind.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6;
         _admission = new AgentAdmission(_streams);
         _udp = new UdpMux(_sessions, _admission, _clock, _counters.Data, log, bind, config.Listen.UdpPorts);
         _tcp = new TcpAcceptor(bind, config.Listen.TcpPorts, identity.Certificate, _sessions, _counters.Data);
@@ -257,6 +264,7 @@ public sealed class AgentApp : IDisposable
     {
         var meta = new AgentHelloMeta
         {
+            Ipv6Supported = _ipv6Supported,
             Platform = MoShiro.Measurement.PlatformDetector.Detect(),
             TlsSpki = _identity.File.TlsSpki,
             ProbeTcpPort = ControlPort,
diff --git a/backend/agent/src/MoShiro.Agent/AgentConfig.cs b/backend/agent/src/MoShiro.Agent/AgentConfig.cs
index cc89cb3..1331b8d 100644
--- a/backend/agent/src/MoShiro.Agent/AgentConfig.cs
+++ b/backend/agent/src/MoShiro.Agent/AgentConfig.cs
@@ -46,7 +46,7 @@ public sealed class FleetSection
 public sealed class ListenSection
 {
     [JsonPropertyName("bind")]
-    public string Bind { get; set; } = "0.0.0.0";
+    public string Bind { get; set; } = "::";
 
     /// <summary>Probe 控制通道（TLS，点对点会话）。</summary>
     [JsonPropertyName("control_port")]
diff --git a/backend/agent/src/MoShiro.Agent/Chunks/ChunkAssembler.cs b/backend/agent/src/MoShiro.Agent/Chunks/ChunkAssembler.cs
index 21f050e..5753a42 100644
--- a/backend/agent/src/MoShiro.Agent/Chunks/ChunkAssembler.cs
+++ b/backend/agent/src/MoShiro.Agent/Chunks/ChunkAssembler.cs
@@ -44,6 +44,7 @@ public sealed class ChunkAssembler
             _ => null,
         };
         header.ProbeId = new ProbeId(probe.ProbeId);
+        header.IpVersion = probe.IpVersion; // 地址族以认证过的控制会话为准，不接受列块自报值
         KindSpec? spec = stream is null ? null : Kinds.Find(stream.Kind);
         if (stream is null || spec is null || spec.Id != header.Kind)
         {
diff --git a/backend/agent/src/MoShiro.Agent/DataPlane/Registries.cs b/backend/agent/src/MoShiro.Agent/DataPlane/Registries.cs
index 5703c4d..b467648 100644
--- a/backend/agent/src/MoShiro.Agent/DataPlane/Registries.cs
+++ b/backend/agent/src/MoShiro.Agent/DataPlane/Registries.cs
@@ -56,6 +56,10 @@ public sealed class ProbeSession : DataSession
 
     public string ProbeId => Info.PeerId;
 
+    public string IpVersion => Info.Remote is IPEndPoint endpoint && endpoint.Address.AddressFamily == AddressFamily.InterNetworkV6 && !endpoint.Address.IsIPv4MappedToIPv6 ? IpVersions.V6 : IpVersions.V4;
+
+    public string PathKey => ProbeId + "~" + IpVersion;
+
     /// <summary>Probe 的程序版本（握手里自报，只用于展示）。</summary>
     public string? Version => Info.Version;
 
@@ -72,7 +76,7 @@ public sealed class ProbeSession : DataSession
         get
         {
             SocketAddress? source = Volatile.Read(ref _udpSource);
-            return source is null ? null : (IPEndPoint)new IPEndPoint(IPAddress.Any, 0).Create(source);
+            return source is null ? null : (IPEndPoint)new IPEndPoint(source.Family == AddressFamily.InterNetworkV6 ? IPAddress.IPv6Any : IPAddress.Any, 0).Create(source);
         }
     }
 
@@ -125,7 +129,7 @@ public sealed class ProbeSession : DataSession
     public void ForgetStream(uint streamId) => _windows.TryRemove(streamId, out _);
 }
 
-/// <summary>当前连着的 Probe 会话：每个 Probe 一个；同一个 Probe 重连时新会话取代它自己的旧会话。</summary>
+/// <summary>每个 Probe 的 IPv4、IPv6 会话独立；重连只替换同地址族的旧会话。</summary>
 public sealed class SessionRegistry : IDataSessions
 {
     private readonly object _gate = new();
@@ -143,11 +147,11 @@ public sealed class SessionRegistry : IDataSessions
         }
     }
 
-    public ProbeSession? Get(string probeId)
+    public ProbeSession? Get(string probeId, string ipVersion = IpVersions.V4)
     {
         lock (_gate)
         {
-            return _byProbe.GetValueOrDefault(probeId);
+            return _byProbe.GetValueOrDefault(probeId + "~" + ipVersion);
         }
     }
 
@@ -156,13 +160,13 @@ public sealed class SessionRegistry : IDataSessions
     {
         lock (_gate)
         {
-            _byProbe.TryGetValue(session.ProbeId, out ProbeSession? old);
+            _byProbe.TryGetValue(session.PathKey, out ProbeSession? old);
             if (old is not null)
             {
                 _bySession.Remove(old.SessionId);
             }
 
-            _byProbe[session.ProbeId] = session;
+            _byProbe[session.PathKey] = session;
             _bySession[session.SessionId] = session;
             return old;
         }
@@ -172,9 +176,9 @@ public sealed class SessionRegistry : IDataSessions
     {
         lock (_gate)
         {
-            if (_byProbe.TryGetValue(session.ProbeId, out ProbeSession? current) && ReferenceEquals(current, session))
+            if (_byProbe.TryGetValue(session.PathKey, out ProbeSession? current) && ReferenceEquals(current, session))
             {
-                _byProbe.Remove(session.ProbeId);
+                _byProbe.Remove(session.PathKey);
             }
 
             if (_bySession.TryGetValue(session.SessionId, out ProbeSession? bySession) && ReferenceEquals(bySession, session))
diff --git a/backend/agent/src/MoShiro.Agent/Peer/PeerHub.cs b/backend/agent/src/MoShiro.Agent/Peer/PeerHub.cs
index b390d6d..77acdd2 100644
--- a/backend/agent/src/MoShiro.Agent/Peer/PeerHub.cs
+++ b/backend/agent/src/MoShiro.Agent/Peer/PeerHub.cs
@@ -176,7 +176,7 @@ public sealed class PeerHub
             await _tasks.CloseSessionAsync(probe);
             _log.Info("probe disconnected", ("probe", info.PeerId));
             OnProbeLost?.Invoke(probe);
-            await _uplink.EmitEventAsync(AgentEventKinds.ProbeDisconnected, info.PeerId);
+            await _uplink.EmitEventAsync(AgentEventKinds.ProbeDisconnected, info.PeerId, Describe(probe));
         }
     }
 
@@ -208,7 +208,7 @@ public sealed class PeerHub
     /// <summary>当前连着的 Probe（心跳和 Backend 重连之后的补报都用它）。</summary>
     public IReadOnlyList<ConnectedProbe> ConnectedProbes() => [.. _sessions.All.Select(Describe)];
 
-    private static ConnectedProbe Describe(ProbeSession p) => new() { Id = new ProbeId(p.ProbeId), Version = p.Version, Remote = p.RemoteAddress, SinceUtcMs = p.ConnectedAtUtcMs };
+    private static ConnectedProbe Describe(ProbeSession p) => new() { Id = new ProbeId(p.ProbeId), Version = p.Version, Remote = p.RemoteAddress, SinceUtcMs = p.ConnectedAtUtcMs, IpVersion = p.IpVersion };
 
     public IReadOnlyList<string> ConnectedProbeIds() => [.. _sessions.All.Select(p => p.ProbeId)];
 
@@ -218,13 +218,17 @@ public sealed class PeerHub
     /// <summary>Backend 要求断开某个 Probe（它会按退避重连，除非已经被吊销）。没有这个会话时返回 false。</summary>
     public async ValueTask<bool> DisconnectAsync(string probeId)
     {
-        if (_sessions.Get(probeId)?.Rpc is not { } rpc)
+        bool disconnected = false;
+        foreach (ProbeSession probe in _sessions.All)
         {
-            return false;
+            if (probe.ProbeId == probeId && probe.Rpc is { } rpc)
+            {
+                await rpc.CloseAsync("disconnected", CancellationToken.None);
+                disconnected = true;
+            }
         }
 
-        await rpc.CloseAsync("disconnected", CancellationToken.None);
-        return true;
+        return disconnected;
     }
 
     /// <summary>名单（期望状态里的 peers）里已经没有的 Probe：立刻关闭它的会话（吊销生效）。</summary>
diff --git a/backend/agent/src/MoShiro.Agent/Tasks/TargetRunners.cs b/backend/agent/src/MoShiro.Agent/Tasks/TargetRunners.cs
index a5dbf29..5ee48b0 100644
--- a/backend/agent/src/MoShiro.Agent/Tasks/TargetRunners.cs
+++ b/backend/agent/src/MoShiro.Agent/Tasks/TargetRunners.cs
@@ -80,7 +80,7 @@ public sealed class TargetRunners
                 Log = _log,
                 Session = () => null,
                 PeerAddress = address,
-                Fragments = new LocalSink(this, spec),
+                Fragments = new LocalSink(this, spec, address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 ? IpVersions.V6 : IpVersions.V4),
             };
             IBlock block = BlockCatalog.Find(spec.Kind)!.Dialer(env, new BlockSpec(decision.Kind!, decision.Resolved!, 0, port, new FragmentScope(spec.Id, null, null)));
             using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
@@ -132,11 +132,13 @@ public sealed class TargetRunners
     {
         private readonly TargetRunners _owner;
         private readonly TaskSpec _spec;
+        private readonly string _ipVersion;
 
-        public LocalSink(TargetRunners owner, TaskSpec spec)
+        public LocalSink(TargetRunners owner, TaskSpec spec, string ipVersion)
         {
             _owner = owner;
             _spec = spec;
+            _ipVersion = ipVersion;
         }
 
         public void Ship(string kind, FragmentScope scope, IReadOnlyList<RawStream> streams, IReadOnlyDictionary<string, JsonElement>? parameters, long startUtcMs, int durationMs, int port)
@@ -149,6 +151,7 @@ public sealed class TargetRunners
                 TaskId = scope.Task,
                 AgentId = _owner._agent,
                 Target = _spec.Target,
+                IpVersion = _ipVersion,
                 Params = parameters is null ? [] : new Dictionary<string, JsonElement>(parameters),
                 Port = port,
                 StartUtcMs = startUtcMs,
diff --git a/backend/agent/src/MoShiro.Agent/Tests/TestRunner.cs b/backend/agent/src/MoShiro.Agent/Tests/TestRunner.cs
index 23c2ddc..745a8bc 100644
--- a/backend/agent/src/MoShiro.Agent/Tests/TestRunner.cs
+++ b/backend/agent/src/MoShiro.Agent/Tests/TestRunner.cs
@@ -46,7 +46,12 @@ public sealed class TestRunner
     /// <summary>校验并接受一个测试（立即返回），实际运行在后台进行，状态通过 <c>moshiro.test.status</c> 回报。</summary>
     public Result<TestRunResult> Start(TestRunParams run)
     {
-        if (_sessions.Get(run.ProbeId.Value) is not { } probe)
+        if (!IpVersions.IsValid(run.IpVersion))
+        {
+            return Result<TestRunResult>.Fail(MoShiroErrors.ValidationFailed, "ip_version must be ipv4 or ipv6");
+        }
+
+        if (_sessions.Get(run.ProbeId.Value, run.IpVersion) is not { } probe)
         {
             return Result<TestRunResult>.Fail(MoShiroErrors.ProbeOffline, $"probe {run.ProbeId.Value} is not connected to this agent");
         }
diff --git a/backend/fleet/src/Fleet.Link/Peer.cs b/backend/fleet/src/Fleet.Link/Peer.cs
index e26dbcb..691b544 100644
--- a/backend/fleet/src/Fleet.Link/Peer.cs
+++ b/backend/fleet/src/Fleet.Link/Peer.cs
@@ -57,6 +57,11 @@ public sealed class PeerListener
     public async Task RunAsync(CancellationToken ct)
     {
         var listener = new TcpListener(_options.Listen);
+        if (_options.Listen.Address.Equals(IPAddress.IPv6Any))
+        {
+            listener.Server.DualMode = true;
+        }
+
         listener.Start();
         Port = ((IPEndPoint)listener.LocalEndpoint).Port;
         Started.TrySetResult();
@@ -219,7 +224,8 @@ public static class PeerConnector
     public static async Task<(PeerSessionInfo Info, TlsFrameTransport Transport)> ConnectAsync(
         string host, int port, byte[] expectedSpkiSha256, NodeIdentity identity, string peerId, string? version, int maxFrameBytes, TimeProvider time, CancellationToken ct)
     {
-        var client = new TcpClient { NoDelay = true };
+        TcpClient client = IPAddress.TryParse(host, out IPAddress? address) ? new TcpClient(address.AddressFamily) : new TcpClient();
+        client.NoDelay = true;
         PeerSockets.EnableKeepAlive(client.Client);
         try
         {
diff --git a/backend/openapi/v1.json b/backend/openapi/v1.json
index fb33894..8d0221d 100644
--- a/backend/openapi/v1.json
+++ b/backend/openapi/v1.json
@@ -61,6 +61,13 @@
             "schema": {
               "type": "string"
             }
+          },
+          {
+            "name": "ip_version",
+            "in": "query",
+            "schema": {
+              "type": "string"
+            }
           }
         ],
         "responses": {
@@ -706,6 +713,15 @@
         ],
         "summary": "Server-sent events: nodes, overview, series and test topics",
         "operationId": "live_stream",
+        "parameters": [
+          {
+            "name": "ip_version",
+            "in": "query",
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
         "responses": {
           "200": {
             "description": "OK"
@@ -4333,6 +4349,14 @@
           },
           "last_seen_at": {
             "format": "date-time"
+          },
+          "ipv6_host": {
+            "type": "string",
+            "default": ""
+          },
+          "ipv6_supported": {
+            "type": "boolean",
+            "default": false
           }
         }
       },
@@ -4371,6 +4395,12 @@
               "null",
               "boolean"
             ]
+          },
+          "ipv6_host": {
+            "type": [
+              "null",
+              "string"
+            ]
           }
         }
       },
@@ -4624,6 +4654,10 @@
           },
           "connected_since": {
             "format": "date-time"
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
           }
         }
       },
@@ -5555,6 +5589,14 @@
                 "$ref": "#/components/schemas/TestSummaryDto"
               }
             ]
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
+          },
+          "ipv6_available": {
+            "type": "boolean",
+            "default": false
           }
         }
       },
@@ -6131,6 +6173,10 @@
                 "$ref": "#/components/schemas/TestSummaryDto"
               }
             ]
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
           }
         }
       },
@@ -6727,6 +6773,10 @@
           },
           "connected_since": {
             "format": "date-time"
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
           }
         }
       },
@@ -7206,6 +7256,10 @@
             "additionalProperties": {
               "type": "string"
             }
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
           }
         }
       },
@@ -7458,6 +7512,10 @@
                 "$ref": "#/components/schemas/TestResultDto"
               }
             ]
+          },
+          "ip_version": {
+            "type": "string",
+            "default": "ipv4"
           }
         }
       },
diff --git a/backend/probe/src/MoShiro.Probe/Link/AgentConnection.cs b/backend/probe/src/MoShiro.Probe/Link/AgentConnection.cs
index 1a2e621..b574a36 100644
--- a/backend/probe/src/MoShiro.Probe/Link/AgentConnection.cs
+++ b/backend/probe/src/MoShiro.Probe/Link/AgentConnection.cs
@@ -74,8 +74,20 @@ public sealed class AgentConnection
 
     private async Task<string> RunOnceAsync(Backoff backoff, CancellationToken ct)
     {
+        AddressFamily family = Endpoint.IpVersion == IpVersions.V6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork;
+        using var resolveTimeout = new CancellationTokenSource(TimeSpan.FromSeconds(10), _env.Time);
+        using CancellationTokenSource resolveCt = CancellationTokenSource.CreateLinkedTokenSource(ct, resolveTimeout.Token);
+        IPAddress[] addresses = IPAddress.TryParse(Endpoint.Host, out IPAddress? literal)
+            ? [literal]
+            : await Dns.GetHostAddressesAsync(Endpoint.Host, family, resolveCt.Token);
+        IPAddress? address = addresses.FirstOrDefault(a => a.AddressFamily == family && !a.IsIPv4MappedToIPv6);
+        if (address is null)
+        {
+            throw new SocketException((int)SocketError.HostNotFound);
+        }
+
         (PeerSessionInfo info, TlsFrameTransport transport) = await PeerConnector.ConnectAsync(
-            Endpoint.Host, Endpoint.TcpPort, Convert.FromBase64String(Endpoint.Spki), _env.Identity, _env.ProbeId, ProbeApp.Version, 8 << 20, _env.Time, ct);
+            address.ToString(), Endpoint.TcpPort, Convert.FromBase64String(Endpoint.Spki), _env.Identity, _env.ProbeId, ProbeApp.Version, 8 << 20, _env.Time, ct);
         var remote = (IPEndPoint)info.Remote!;
         var data = new DataSession(info.Credentials.SessionIdValue, info.Credentials.Key);
         using var udp = new UdpMux(new SingleSession(data), null, _env.Clock, new DataPlaneCounters(), _env.Log, remote.AddressFamily == AddressFamily.InterNetworkV6 ? IPAddress.IPv6Any : IPAddress.Any, []);
diff --git a/backend/probe/src/MoShiro.Probe/Link/AgentDirectory.cs b/backend/probe/src/MoShiro.Probe/Link/AgentDirectory.cs
index 4a59d2c..e41904f 100644
--- a/backend/probe/src/MoShiro.Probe/Link/AgentDirectory.cs
+++ b/backend/probe/src/MoShiro.Probe/Link/AgentDirectory.cs
@@ -67,7 +67,19 @@ public sealed class AgentDirectory
     /// <summary>应用面板下发的列表。版本不比当前新的忽略（乱序到达的旧推送）。</summary>
     public void Apply(ProbeAgentList result)
     {
-        var next = result.Agents.Select(a => new KnownAgent { AgentId = a.AgentId.Value, Host = a.Host, TcpPort = a.TcpPort, Spki = a.Spki }).ToList();
+        var next = new List<KnownAgent>();
+        foreach (AgentEndpoint agent in result.Agents)
+        {
+            if (!string.IsNullOrWhiteSpace(agent.Host))
+            {
+                next.Add(new KnownAgent { AgentId = agent.AgentId.Value, Host = agent.Host, TcpPort = agent.TcpPort, Spki = agent.Spki });
+            }
+
+            if (!string.IsNullOrWhiteSpace(agent.Ipv6Host))
+            {
+                next.Add(new KnownAgent { AgentId = agent.AgentId.Value, Host = agent.Ipv6Host, TcpPort = agent.TcpPort, Spki = agent.Spki, IpVersion = IpVersions.V6 });
+            }
+        }
         lock (_gate)
         {
             if (result.Version < _version || (result.Version == _version && Same(next, _agents)))
@@ -96,5 +108,5 @@ public sealed class AgentDirectory
         a.Count == b.Count && a.Zip(b).All(p => Equal(p.First, p.Second));
 
     public static bool Equal(KnownAgent a, KnownAgent b) =>
-        a.AgentId == b.AgentId && a.Host == b.Host && a.TcpPort == b.TcpPort && a.Spki == b.Spki;
+        a.AgentId == b.AgentId && a.IpVersion == b.IpVersion && a.Host == b.Host && a.TcpPort == b.TcpPort && a.Spki == b.Spki;
 }
diff --git a/backend/probe/src/MoShiro.Probe/ProbeApp.cs b/backend/probe/src/MoShiro.Probe/ProbeApp.cs
index 9ffb699..d376c21 100644
--- a/backend/probe/src/MoShiro.Probe/ProbeApp.cs
+++ b/backend/probe/src/MoShiro.Probe/ProbeApp.cs
@@ -70,19 +70,19 @@ public sealed class ProbeApp : IDisposable
     public AgentDirectory Directory => _env.Directory;
 
     /// <summary>某个 Agent 的会话是否已经建立（测试和状态查看用）。</summary>
-    public bool IsConnected(string agentId)
+    public bool IsConnected(string agentId, string ipVersion = IpVersions.V4)
     {
         lock (_connections)
         {
-            return _connections.TryGetValue(agentId, out Running? running) && running.Connection.IsConnected;
+            return _connections.TryGetValue(agentId + "~" + ipVersion, out Running? running) && running.Connection.IsConnected;
         }
     }
 
-    public AgentConnection? Connection(string agentId)
+    public AgentConnection? Connection(string agentId, string ipVersion = IpVersions.V4)
     {
         lock (_connections)
         {
-            return _connections.TryGetValue(agentId, out Running? running) ? running.Connection : null;
+            return _connections.TryGetValue(agentId + "~" + ipVersion, out Running? running) ? running.Connection : null;
         }
     }
 
@@ -121,7 +121,7 @@ public sealed class ProbeApp : IDisposable
 
     private async Task ReconcileAsync(IReadOnlyList<KnownAgent> agents, CancellationToken ct)
     {
-        var wanted = agents.ToDictionary(a => a.AgentId);
+        var wanted = agents.ToDictionary(a => a.PathKey);
         var stopped = new List<Running>();
         lock (_connections)
         {
diff --git a/backend/probe/src/MoShiro.Probe/ProbeConfig.cs b/backend/probe/src/MoShiro.Probe/ProbeConfig.cs
index 5bb9aa8..1057d90 100644
--- a/backend/probe/src/MoShiro.Probe/ProbeConfig.cs
+++ b/backend/probe/src/MoShiro.Probe/ProbeConfig.cs
@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using MoShiro.Protocol;
 
 namespace MoShiro.Probe;
 
@@ -25,6 +26,12 @@ public sealed class ProbeFile
 
 public sealed class KnownAgent
 {
+    [JsonPropertyName("ip_version")]
+    public string IpVersion { get; set; } = IpVersions.V4;
+
+    [JsonIgnore]
+    public string PathKey => AgentId + "~" + IpVersion;
+
     [JsonPropertyName("agent_id")]
     public string AgentId { get; set; } = "";
 
diff --git a/backend/probe/tests/MoShiro.Probe.Tests/ProbeTests.cs b/backend/probe/tests/MoShiro.Probe.Tests/ProbeTests.cs
index 5ff35e8..3b9825f 100644
--- a/backend/probe/tests/MoShiro.Probe.Tests/ProbeTests.cs
+++ b/backend/probe/tests/MoShiro.Probe.Tests/ProbeTests.cs
@@ -6,6 +6,31 @@ namespace MoShiro.Probe.Tests;
 
 public sealed class ProbeTests
 {
+    [Fact]
+    public void AgentDirectory_DualStack_PersistsBothPaths_AndRemovingIpv6KeepsIpv4()
+    {
+        string directory = NewDirectory();
+        try
+        {
+            var agents = new AgentDirectory(new ConfigStore(directory), directory, NullNodeLog.Instance);
+            ProbeAgentList list = List(1, "agt_dual");
+            list.Agents[0].Ipv6Host = "2001:db8::1";
+            agents.Apply(list);
+            Assert.Equal(new[] { "ipv4", "ipv6" }, agents.Agents.Select(a => a.IpVersion));
+            var reloaded = new AgentDirectory(new ConfigStore(directory), directory, NullNodeLog.Instance);
+            Assert.Equal(2, reloaded.Agents.Count);
+            Assert.Equal("2001:db8::1", reloaded.Agents[1].Host);
+            list.Version = 2;
+            list.Agents[0].Ipv6Host = null;
+            reloaded.Apply(list);
+            Assert.Equal("ipv4", Assert.Single(reloaded.Agents).IpVersion);
+        }
+        finally
+        {
+            Directory.Delete(directory, recursive: true);
+        }
+    }
+
     [Fact]
     public void ClockEstimator_UsesTheSampleWithTheShortestRoundTrip()
     {
diff --git a/backend/shared/MoShiro.Measurement/Merging/ChunkFinalizer.cs b/backend/shared/MoShiro.Measurement/Merging/ChunkFinalizer.cs
index 53379cb..f4591c3 100644
--- a/backend/shared/MoShiro.Measurement/Merging/ChunkFinalizer.cs
+++ b/backend/shared/MoShiro.Measurement/Merging/ChunkFinalizer.cs
@@ -69,6 +69,7 @@ public static class ChunkFinalizer
             Phase = source.Phase,
             AgentId = agent,
             ProbeId = source.ProbeId,
+            IpVersion = source.IpVersion,
             Target = null,
             Params = new Dictionary<string, JsonElement>(resolvedParams),
             Port = port,
diff --git a/backend/shared/MoShiro.Measurement/Net/Tcp.cs b/backend/shared/MoShiro.Measurement/Net/Tcp.cs
index 30adafb..98e798b 100644
--- a/backend/shared/MoShiro.Measurement/Net/Tcp.cs
+++ b/backend/shared/MoShiro.Measurement/Net/Tcp.cs
@@ -39,7 +39,7 @@ public sealed class TcpLink : IDisposable
     /// </summary>
     public static async Task<TcpLink> OpenAsync(BlockEnv env, int port, bool tls, uint streamId, bool sendAuth, CancellationToken ct)
     {
-        var client = new TcpClient { NoDelay = true };
+        var client = new TcpClient(env.PeerAddress!.AddressFamily) { NoDelay = true };
         try
         {
             long start = env.Clock.NowUs();
@@ -153,6 +153,11 @@ public sealed class TcpAcceptor
         foreach (int port in _ports)
         {
             var listener = new TcpListener(_bind, port);
+            if (_bind.Equals(IPAddress.IPv6Any))
+            {
+                listener.Server.DualMode = true;
+            }
+
             listener.Start(128);
             _listeners.Add(listener);
             bound.Add(((IPEndPoint)listener.LocalEndpoint).Port);
diff --git a/backend/shared/MoShiro.Protocol/IpVersions.cs b/backend/shared/MoShiro.Protocol/IpVersions.cs
new file mode 100644
index 0000000..a7880dc
--- /dev/null
+++ b/backend/shared/MoShiro.Protocol/IpVersions.cs
@@ -0,0 +1,13 @@
+namespace MoShiro.Protocol;
+
+/// <summary>测量路径的地址族。旧契约缺省为 IPv4；IPv6 使用独立的线路和序列。</summary>
+public static class IpVersions
+{
+    public const string V4 = "ipv4";
+    public const string V6 = "ipv6";
+
+    public static bool IsValid(string? value) => value is V4 or V6;
+
+    public static string LineSeries(string probeId, string ipVersion) =>
+        RawChunkHeader.LinePrefix + probeId + (ipVersion == V6 ? ":ipv6" : "");
+}
diff --git a/backend/shared/MoShiro.Protocol/Raw/RawChunk.cs b/backend/shared/MoShiro.Protocol/Raw/RawChunk.cs
index 0255d66..e7c11ad 100644
--- a/backend/shared/MoShiro.Protocol/Raw/RawChunk.cs
+++ b/backend/shared/MoShiro.Protocol/Raw/RawChunk.cs
@@ -58,6 +58,10 @@ public sealed class StreamHeader
 /// <summary>块头（JSON，自描述）：列定义写在块里，新增列或新增 Kind 不需要升级 container_version。</summary>
 public sealed class RawChunkHeader
 {
+    [JsonPropertyName("ip_version")]
+    [JsonPropertyOrder(1)]
+    public string IpVersion { get; set; } = IpVersions.V4;
+
     [JsonPropertyName("chunk_id")]
     public ChunkId ChunkId { get; set; }
 
@@ -113,10 +117,10 @@ public sealed class RawChunkHeader
 
     /// <summary>
     /// "line:&lt;probe_id&gt;" 或 "target:&lt;task_id&gt;"：存储和分析用的序列标识。
-    /// 一条线路是一对（Probe，Agent）：同一个 Agent 上每个 Probe 的数据各是一个序列，互不混合。
+    /// 同一个 Agent 上每个 Probe 的每种地址族各是一个序列，IPv6 追加 :ipv6，互不混合。
     /// </summary>
     [JsonIgnore]
-    public string Series => TaskId is { } id && Target is not null ? "target:" + id.Value : LinePrefix + (ProbeId?.Value ?? "");
+    public string Series => TaskId is { } id && Target is not null ? "target:" + id.Value : IpVersions.LineSeries(ProbeId?.Value ?? "", IpVersion);
 
     public const string LinePrefix = "line:";
 }
diff --git a/backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs b/backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs
index 83864cc..e0e66a4 100644
--- a/backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs
+++ b/backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs
@@ -61,6 +61,9 @@ public sealed class TestPhase
 
 public sealed class TestRunParams
 {
+    [JsonPropertyName("ip_version")]
+    public string IpVersion { get; set; } = IpVersions.V4;
+
     [JsonPropertyName("test_id")]
     public TestId TestId { get; set; }
 
@@ -127,6 +130,9 @@ public sealed class AgentEventParams
 
 public sealed class AgentEndpoint
 {
+    [JsonPropertyName("ipv6_host")]
+    public string? Ipv6Host { get; set; }
+
     [JsonPropertyName("agent_id")]
     public NodeId AgentId { get; set; }
 
@@ -289,6 +295,10 @@ public sealed class ProbeHelloMeta
 /// <summary><c>fleet.hello</c> 的附加字段。</summary>
 public sealed class AgentHelloMeta
 {
+    /// <summary>本机是否启用了 IPv6 监听。旧 Agent 缺省为 false，面板不会给它安排 IPv6 会话。</summary>
+    [JsonPropertyName("ipv6_supported")]
+    public bool Ipv6Supported { get; set; }
+
     [JsonPropertyName("platform")]
     public PlatformInfo? Platform { get; set; }
 
@@ -353,6 +363,9 @@ public sealed class HostSnapshot
 /// <summary>Agent 眼中的一个已连接 Probe。</summary>
 public sealed class ConnectedProbe
 {
+    [JsonPropertyName("ip_version")]
+    public string IpVersion { get; set; } = IpVersions.V4;
+
     [JsonPropertyName("id")]
     public ProbeId Id { get; set; }
 
diff --git a/backend/shared/tests/MoShiro.Protocol.Tests/RawChunkCodecTests.cs b/backend/shared/tests/MoShiro.Protocol.Tests/RawChunkCodecTests.cs
index 1f659ec..06eb7e8 100644
--- a/backend/shared/tests/MoShiro.Protocol.Tests/RawChunkCodecTests.cs
+++ b/backend/shared/tests/MoShiro.Protocol.Tests/RawChunkCodecTests.cs
@@ -8,6 +8,21 @@ namespace MoShiro.Protocol.Tests;
 
 public sealed class RawChunkCodecTests
 {
+    [Fact]
+    public void Header_LegacyDefaultsToIpv4_AndIpv6RoundTripsToAnIndependentSeries()
+    {
+        RawChunkHeader legacy = System.Text.Json.JsonSerializer.Deserialize("{\"probe_id\":\"prb_legacy\"}", MoShiroJsonContext.Default.RawChunkHeader)!;
+        Assert.Equal(IpVersions.V4, legacy.IpVersion);
+        Assert.Equal("line:prb_legacy", legacy.Series);
+        RawChunk chunk = SampleChunk();
+        chunk.Header.ProbeId = new ProbeId("prb_dual");
+        chunk.Header.IpVersion = IpVersions.V6;
+        RawChunk decoded = RawChunkCodec.Decode(RawChunkCodec.Encode(chunk)).Value;
+        Assert.Equal("ipv6", decoded.Header.IpVersion);
+        Assert.Equal("line:prb_dual:ipv6", decoded.Header.Series);
+        Assert.Equal(chunk.Find("msg")!.Count, decoded.Find("msg")!.Count);
+    }
+
     private static readonly NodeId s_agent = new("agt_test");
 
     private static RawChunk SampleChunk()
diff --git a/backend/src/MoShiro.Backend.Api/Admin/AgentEndpoints.cs b/backend/src/MoShiro.Backend.Api/Admin/AgentEndpoints.cs
index 9360dd0..5aa566e 100644
--- a/backend/src/MoShiro.Backend.Api/Admin/AgentEndpoints.cs
+++ b/backend/src/MoShiro.Backend.Api/Admin/AgentEndpoints.cs
@@ -87,7 +87,7 @@ public static class AgentEndpoints
     private static async Task<IResult> PatchAsync(HttpContext http, AgentService agents, AgentPatchRequest request, string id, CancellationToken ct)
     {
         Result<AgentView> result = await agents.PatchAsync(
-            new NodeId(id), new AgentPatch { Name = request.Name, Labels = request.Labels, PublicHost = request.PublicHost, PublicVisible = request.PublicVisible }, Concurrency.ExpectedRowVersion(http), ct);
+            new NodeId(id), new AgentPatch { Name = request.Name, Labels = request.Labels, PublicHost = request.PublicHost, Ipv6Host = request.Ipv6Host, PublicVisible = request.PublicVisible }, Concurrency.ExpectedRowVersion(http), ct);
         if (!result.TryGet(out AgentView? view, out FleetError? error))
         {
             return Problems.From(http, error);
diff --git a/backend/src/MoShiro.Backend.Api/Admin/TaskEndpoints.cs b/backend/src/MoShiro.Backend.Api/Admin/TaskEndpoints.cs
index 66b8c41..f6fc4a1 100644
--- a/backend/src/MoShiro.Backend.Api/Admin/TaskEndpoints.cs
+++ b/backend/src/MoShiro.Backend.Api/Admin/TaskEndpoints.cs
@@ -109,7 +109,7 @@ public static class TaskEndpoints
             return Problems.From(http, lineError);
         }
 
-        Result<TestRecord> result = await tests.StartAsync(line.Key.Agent, line.Key.Probe, new StartTestRequest(request.Plan ?? "", request.Params), "api", ct);
+        Result<TestRecord> result = await tests.StartAsync(line.Key.Agent, line.Key.Probe, new StartTestRequest(request.Plan ?? "", request.Params), "api", line.IpVersion, ct);
         if (!result.TryGet(out TestRecord? test, out FleetError? error))
         {
             return Problems.From(http, error);
@@ -124,10 +124,12 @@ public static class TaskEndpoints
         // 只给 Agent id（并且有多个 Probe）时列出这个 Agent 上所有 Probe 的测试
         NodeId agent;
         ProbeId? probe = null;
+        string? ipVersion = null;
         if (LineKey.TryParse(line_id, out LineKey key))
         {
             agent = key.Agent;
             probe = key.Probe;
+            ipVersion = key.IpVersion;
         }
         else
         {
@@ -135,7 +137,7 @@ public static class TaskEndpoints
         }
 
         return TypedResults.Json(
-            new PageDto<TestDto>([.. (await tests.ListAsync(agent, probe, Math.Clamp(limit ?? 50, 1, 500), ct)).Select(Mappers.ToDto)], null),
+            new PageDto<TestDto>([.. (await tests.ListAsync(agent, probe, Math.Clamp(limit ?? 50, 1, 500), ipVersion, ct)).Select(Mappers.ToDto)], null),
             ApiJsonContext.Default.PageDtoTestDto);
     }
 
diff --git a/backend/src/MoShiro.Backend.Api/Common/Mappers.cs b/backend/src/MoShiro.Backend.Api/Common/Mappers.cs
index 39fd43e..2784074 100644
--- a/backend/src/MoShiro.Backend.Api/Common/Mappers.cs
+++ b/backend/src/MoShiro.Backend.Api/Common/Mappers.cs
@@ -31,34 +31,34 @@ public static class Mappers
     public static OverviewLineDto ToDto(OverviewLine line) =>
         new(
             line.Line.Key.Id, line.Line.Agent.Agent.Id.Value, line.Line.Probe.Id, line.Line.Probe.Name, line.Line.Agent.Agent.Name, line.Line.Agent.Agent.Labels,
-            line.Line.Agent.Online, line.Line.Connected, line.Line.Agent.EndpointChanges, ToDto(line.Summary), Summary(line.LastTest));
+            line.Line.Agent.Online, line.Line.Connected, line.Line.Agent.EndpointChanges, ToDto(line.Summary), Summary(line.LastTest), line.Line.IpVersion);
 
     public static HostDto ToDto(HostSnapshot h) =>
         new(h.CpuPercent, h.MemUsed, h.MemTotal, h.DiskUsed, h.DiskTotal, h.NetRxTotal, h.NetTxTotal, h.NetRxBps, h.NetTxBps, h.NetLinkMbps, h.UptimeSeconds, Time(h.AtUtcMs));
 
-    public static ConnectedProbeDto ToDto(ConnectedProbeInfo p) => new(p.Id, p.Version, p.Remote, Time(p.SinceMs));
+    public static ConnectedProbeDto ToDto(ConnectedProbeInfo p) => new(p.Id, p.Version, p.Remote, Time(p.SinceMs), p.IpVersion);
 
     public static ProbeDto ToDto(ProbeView v) =>
         new(
             v.Probe.Id, v.Probe.Name, Time(v.Probe.CreatedAtMs), Time(v.Probe.RevokedAtMs), v.Revoked, v.Online,
-            [.. v.Connections.Select(c => new ProbeConnectionDto(c.AgentId.Value, c.AgentName, c.AgentOnline, c.Version, c.Remote, Time(c.SinceMs)))]);
+            [.. v.Connections.Select(c => new ProbeConnectionDto(c.AgentId.Value, c.AgentName, c.AgentOnline, c.Version, c.Remote, Time(c.SinceMs), c.IpVersion))]);
 
     public static SeriesDto ToDto(SeriesResult r, bool live) =>
         new(
             r.Line.Id, r.Line.Agent.Value, r.Line.Probe.Value, Time(r.Range.FromMs), Time(r.Range.ToMs), Steps.Format(r.Range.StepMs), r.Plan.Name, live && r.Range.IsRelative, r.Plan.Degraded,
             r.T, r.Values, ToDto(r.Summary), new EdgePartialDto(r.Range.FirstPartial, r.Range.LastPartial),
-            [.. r.Gaps.Select(g => new GapDto(Time(g.FromMs), Time(g.ToMs), g.Reason))], [.. r.Events.Select(ToDto)], r.Versions);
+            [.. r.Gaps.Select(g => new GapDto(Time(g.FromMs), Time(g.ToMs), g.Reason))], [.. r.Events.Select(ToDto)], r.Versions, r.Line.IpVersion);
 
     public static TestDto ToDto(TestDetail detail)
     {
         TestRecord t = detail.Test;
         return new TestDto(
             t.Id.Value, t.AgentId.Value, t.ProbeId.Value, t.Plan, detail.PhaseKinds, t.Status, t.Phase, t.ErrorCode, t.Trigger,
-            Time(t.RequestedAtMs), Time(t.StartedAtMs), Time(t.FinishedAtMs), detail.Result is null ? null : ToDto(detail.Result));
+            Time(t.RequestedAtMs), Time(t.StartedAtMs), Time(t.FinishedAtMs), detail.Result is null ? null : ToDto(detail.Result), t.IpVersion);
     }
 
     public static TestDto ToDto(TestRecord t) =>
-        new(t.Id.Value, t.AgentId.Value, t.ProbeId.Value, t.Plan, [.. (Plans.Find(t.Plan)?.Phases ?? []).Select(p => p.Kind)], t.Status, t.Phase, t.ErrorCode, t.Trigger, Time(t.RequestedAtMs), Time(t.StartedAtMs), Time(t.FinishedAtMs), null);
+        new(t.Id.Value, t.AgentId.Value, t.ProbeId.Value, t.Plan, [.. (Plans.Find(t.Plan)?.Phases ?? []).Select(p => p.Kind)], t.Status, t.Phase, t.ErrorCode, t.Trigger, Time(t.RequestedAtMs), Time(t.StartedAtMs), Time(t.FinishedAtMs), null, t.IpVersion);
 
     public static TestResultDto ToDto(TestResultView r) =>
         new(
@@ -103,7 +103,7 @@ public static class Mappers
             : null;
         return new AgentDto(
             a.Id.Value, a.Name, StatusName(a.Status), view.Online, view.ProbeConnected, [.. view.Probes.Select(ToDto)], view.Host is null ? null : ToDto(view.Host), a.PublicHost, a.ProbeTcpPort, a.ProbeUdpPorts, a.Labels, a.PublicVisible,
-            a.Kinds, a.AgentVersion, limits, a.TaskVersion, a.AppliedTaskVersion, rejected, heartbeat, view.EndpointChanges, Time(a.CreatedAtMs), Time(a.LastSeenAtMs));
+            a.Kinds, a.AgentVersion, limits, a.TaskVersion, a.AppliedTaskVersion, rejected, heartbeat, view.EndpointChanges, Time(a.CreatedAtMs), Time(a.LastSeenAtMs), a.Ipv6Host, a.Ipv6Supported);
     }
 
     public static TaskDto ToDto(TaskRecord t) =>
diff --git a/backend/src/MoShiro.Backend.Api/Contracts/AdminDtos.cs b/backend/src/MoShiro.Backend.Api/Contracts/AdminDtos.cs
index d01021e..0ad4407 100644
--- a/backend/src/MoShiro.Backend.Api/Contracts/AdminDtos.cs
+++ b/backend/src/MoShiro.Backend.Api/Contracts/AdminDtos.cs
@@ -37,10 +37,12 @@ public sealed record AgentDto(
     HeartbeatDto? Heartbeat,
     int EndpointChanges,
     DateTimeOffset CreatedAt,
-    DateTimeOffset? LastSeenAt);
+    DateTimeOffset? LastSeenAt,
+    string Ipv6Host = "",
+    bool Ipv6Supported = false);
 
 /// <summary>merge-patch：缺省或为 null 的字段不修改。</summary>
-public sealed record AgentPatchRequest(string? Name, IReadOnlyList<string>? Labels, string? PublicHost, bool? PublicVisible);
+public sealed record AgentPatchRequest(string? Name, IReadOnlyList<string>? Labels, string? PublicHost, bool? PublicVisible, string? Ipv6Host = null);
 
 public sealed record JoinTokenDto(string Id, string? Note, IReadOnlyList<string> Labels, bool AutoApprove, int MaxUses, int Uses, DateTimeOffset ExpiresAt, DateTimeOffset? RevokedAt, DateTimeOffset CreatedAt);
 
@@ -52,10 +54,10 @@ public sealed record InstallCommandsDto(string Linux, string Macos, string Windo
 public sealed record CreatedJoinTokenDto(JoinTokenDto Token, string Plaintext, InstallCommandsDto InstallCommands);
 
 /// <summary>Agent 眼中连着的一个 Probe（Agent 上报）。</summary>
-public sealed record ConnectedProbeDto(string ProbeId, string? Version, string? Remote, DateTimeOffset ConnectedSince);
+public sealed record ConnectedProbeDto(string ProbeId, string? Version, string? Remote, DateTimeOffset ConnectedSince, string IpVersion = "ipv4");
 
 /// <summary>某个 Probe 现在连着的一个 Agent。</summary>
-public sealed record ProbeConnectionDto(string AgentId, string AgentName, bool AgentOnline, string? Version, string? Remote, DateTimeOffset ConnectedSince);
+public sealed record ProbeConnectionDto(string AgentId, string AgentName, bool AgentOnline, string? Version, string? Remote, DateTimeOffset ConnectedSince, string IpVersion = "ipv4");
 
 public sealed record ProbeDto(string Id, string Name, DateTimeOffset CreatedAt, DateTimeOffset? RevokedAt, bool Revoked, bool Online, IReadOnlyList<ProbeConnectionDto> Connections);
 
diff --git a/backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs b/backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs
index 4c1cdf0..da47c5e 100644
--- a/backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs
+++ b/backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs
@@ -22,7 +22,8 @@ public sealed record OverviewLineDto(
     bool ProbeConnected,
     int EndpointChanges,
     SummaryDto Summary,
-    TestSummaryDto? LastTest);
+    TestSummaryDto? LastTest,
+    string IpVersion = "ipv4");
 
 public sealed record OverviewDto(string Range, DateTimeOffset From, DateTimeOffset To, string Step, string Source, bool Degraded, IReadOnlyList<OverviewLineDto> Lines);
 
@@ -43,7 +44,8 @@ public sealed record SeriesDto(
     EdgePartialDto EdgePartial,
     IReadOnlyList<GapDto> Gaps,
     IReadOnlyList<EventDto> Events,
-    IReadOnlyDictionary<string, string> Versions);
+    IReadOnlyDictionary<string, string> Versions,
+    string IpVersion = "ipv4");
 
 public sealed record CompareDto(
     string Metric,
@@ -81,7 +83,9 @@ public sealed record LineDto(
     bool ProbeConnected,
     DateTimeOffset? DataSince,
     IReadOnlyList<string> Kinds,
-    TestSummaryDto? LastTest);
+    TestSummaryDto? LastTest,
+    string IpVersion = "ipv4",
+    bool Ipv6Available = false);
 
 public sealed record DimensionDto(string Id, string Label, double Weight, double? Value, double? Score);
 
@@ -109,7 +113,8 @@ public sealed record TestDto(
     DateTimeOffset RequestedAt,
     DateTimeOffset? StartedAt,
     DateTimeOffset? FinishedAt,
-    TestResultDto? Result);
+    TestResultDto? Result,
+    string IpVersion = "ipv4");
 
 // ── 目录（由代码注册表生成） ──────────────────────────────────────────
 
diff --git a/backend/src/MoShiro.Backend.Api/Public/LiveEndpoints.cs b/backend/src/MoShiro.Backend.Api/Public/LiveEndpoints.cs
index b2de354..49ccad4 100644
--- a/backend/src/MoShiro.Backend.Api/Public/LiveEndpoints.cs
+++ b/backend/src/MoShiro.Backend.Api/Public/LiveEndpoints.cs
@@ -33,8 +33,14 @@ public static class LiveEndpoints
 
     private static async Task<IResult> StreamAsync(
         HttpContext http, AgentService agents, LineService lineService, TestService tests, QueryService query, LiveHub hub, SseLimiter limiter,
-        BackendOptions options, BackendCounters counters, TimeProvider time, IHostApplicationLifetime lifetime)
+        BackendOptions options, BackendCounters counters, TimeProvider time, IHostApplicationLifetime lifetime, string? ip_version)
     {
+        string ipVersion = ip_version ?? IpVersions.V4;
+        if (!IpVersions.IsValid(ipVersion))
+        {
+            return Problems.From(http, ValidationError.Single("ip_version", "must be ipv4 or ipv6"));
+        }
+
         StringValues raw = http.Request.Query["topics"];
         Result<IReadOnlyList<LiveTopic>> parsed = LiveTopic.ParseAll(raw.Where(v => v is not null)!, options.MaxSseTopics);
         if (!parsed.TryGet(out IReadOnlyList<LiveTopic>? topics, out FleetError? error))
@@ -78,7 +84,7 @@ public static class LiveEndpoints
             http.Response.Headers["X-Accel-Buffering"] = "no";
             await http.Response.Body.FlushAsync(http.RequestAborted);
 
-            var session = new LiveSession(http, agents, lineService, tests, query, hub, options, time, topics, lineKeys);
+            var session = new LiveSession(http, agents, lineService, tests, query, hub, options, time, topics, lineKeys, ipVersion);
             using var linked = CancellationTokenSource.CreateLinkedTokenSource(http.RequestAborted, lifetime.ApplicationStopping);
             await session.RunAsync(linked.Token);
         }
@@ -101,6 +107,7 @@ public static class LiveEndpoints
         private readonly AgentService _agents;
         private readonly LineService _lines;
         private readonly IReadOnlyDictionary<string, LineKey> _lineKeys;
+        private readonly string _ipVersion;
         private readonly TestService _tests;
         private readonly QueryService _query;
         private readonly LiveHub _hub;
@@ -117,12 +124,13 @@ public static class LiveEndpoints
         private long _lastWriteMs;
         private long _lastPeriodicMs;
 
-        public LiveSession(HttpContext http, AgentService agents, LineService lines, TestService tests, QueryService query, LiveHub hub, BackendOptions options, TimeProvider time, IReadOnlyList<LiveTopic> topics, IReadOnlyDictionary<string, LineKey> lineKeys)
+        public LiveSession(HttpContext http, AgentService agents, LineService lines, TestService tests, QueryService query, LiveHub hub, BackendOptions options, TimeProvider time, IReadOnlyList<LiveTopic> topics, IReadOnlyDictionary<string, LineKey> lineKeys, string ipVersion)
         {
             _http = http;
             _agents = agents;
             _lines = lines;
             _lineKeys = lineKeys;
+            _ipVersion = ipVersion;
             _tests = tests;
             _query = query;
             _hub = hub;
@@ -297,7 +305,7 @@ public static class LiveEndpoints
         {
             MetricSelection selection = MetricSelection.Resolve(null, topic.Preset, _options.MaxMetricsPerQuery).Value;
             IReadOnlyList<LineView> visible = await _lines.ListAsync(a => a.Agent.Status == Fleet.Server.NodeStatus.Active && IsVisible(a), ct);
-            Result<OverviewResult> result = await _query.OverviewAsync(visible, new RangeRequest(topic.Range, null, null, null, null), selection, ct);
+            Result<OverviewResult> result = await _query.OverviewAsync([.. visible.Where(l => l.IpVersion == _ipVersion)], new RangeRequest(topic.Range, null, null, null, null), selection, ct);
             if (result.TryGet(out OverviewResult? overview, out _))
             {
                 var dto = new OverviewDto(
diff --git a/backend/src/MoShiro.Backend.Api/Public/QueryEndpoints.cs b/backend/src/MoShiro.Backend.Api/Public/QueryEndpoints.cs
index 9c8be7d..ad93ce1 100644
--- a/backend/src/MoShiro.Backend.Api/Public/QueryEndpoints.cs
+++ b/backend/src/MoShiro.Backend.Api/Public/QueryEndpoints.cs
@@ -43,9 +43,15 @@ public static class QueryEndpoints
 
     private static Task<IResult> OverviewAsync(
         HttpContext http, LineService lineService, QueryService query, BackendOptions options, TimeProvider time,
-        string? range, DateTimeOffset? from, DateTimeOffset? to, string? preset, string? metrics, string? sort, string? order) =>
+        string? range, DateTimeOffset? from, DateTimeOffset? to, string? preset, string? metrics, string? sort, string? order, string? ip_version) =>
         QueryHelpers.GuardedAsync(http, async ct =>
         {
+            string ipVersion = ip_version ?? IpVersions.V4;
+            if (!IpVersions.IsValid(ipVersion))
+            {
+                return Problems.From(http, ValidationError.Single("ip_version", "must be ipv4 or ipv6"));
+            }
+
             Result<MetricSelection> selection = MetricSelection.Resolve(metrics, preset ?? (metrics is null ? DefaultOverviewPreset : null), options.MaxMetricsPerQuery);
             if (!selection.TryGet(out MetricSelection? sel, out FleetError? error))
             {
@@ -53,7 +59,7 @@ public static class QueryEndpoints
             }
 
             IReadOnlyList<LineView> visible = await lineService.ListAsync(a => a.Agent.Status == Fleet.Server.NodeStatus.Active && (a.Agent.PublicVisible || PublicGuard.CanSeeHidden(http)), ct);
-            Result<OverviewResult> result = await query.OverviewAsync(visible, new RangeRequest(range, from, to, null, null), sel, ct);
+            Result<OverviewResult> result = await query.OverviewAsync([.. visible.Where(l => l.IpVersion == ipVersion)], new RangeRequest(range, from, to, null, null), sel, ct);
             if (!result.TryGet(out OverviewResult? overview, out error))
             {
                 return Problems.From(http, error);
@@ -81,12 +87,12 @@ public static class QueryEndpoints
         }
 
         AgentView view = line.Agent;
-        IReadOnlyList<TestRecord> recent = await tests.ListAsync(view.Agent.Id, new ProbeId(line.Probe.Id), 1, ct);
+        IReadOnlyList<TestRecord> recent = await tests.ListAsync(view.Agent.Id, new ProbeId(line.Probe.Id), 1, line.IpVersion, ct);
         TestRecord? last = recent.Count > 0 ? recent[0] : null;
         return TypedResults.Json(
             new LineDto(
                 line.Key.Id, view.Agent.Id.Value, line.Probe.Id, line.Probe.Name, view.Agent.Name, view.Agent.Labels, view.Online, line.Connected,
-                Mappers.Time(await query.EarliestAsync(line.Key, ct)), view.Agent.Kinds, Mappers.Summary(last)),
+                Mappers.Time(await query.EarliestAsync(line.Key, ct)), view.Agent.Kinds, Mappers.Summary(last), line.IpVersion, view.Agent.Ipv6Host.Length > 0),
             ApiJsonContext.Default.LineDto);
     }
 
diff --git a/backend/src/MoShiro.Backend.Application/Agents/AgentEventService.cs b/backend/src/MoShiro.Backend.Application/Agents/AgentEventService.cs
index 8f50d8b..aec1ee9 100644
--- a/backend/src/MoShiro.Backend.Application/Agents/AgentEventService.cs
+++ b/backend/src/MoShiro.Backend.Application/Agents/AgentEventService.cs
@@ -34,11 +34,11 @@ public sealed class AgentEventService
         switch (e.Kind)
         {
             case AgentEventKinds.ProbeConnected when !string.IsNullOrEmpty(e.Detail):
-                state.AddProbe(e.Probe is { } p ? new ConnectedProbeInfo(e.Detail, p.Version, p.Remote, p.SinceUtcMs > 0 ? p.SinceUtcMs : at) : new ConnectedProbeInfo(e.Detail, null, null, at));
+                state.AddProbe(e.Probe is { } p ? new ConnectedProbeInfo(e.Detail, p.Version, p.Remote, p.SinceUtcMs > 0 ? p.SinceUtcMs : at, p.IpVersion) : new ConnectedProbeInfo(e.Detail, null, null, at));
                 _nodes.ObserveProbeInBackground(e.Detail, e.Probe?.Remote);
                 break;
             case AgentEventKinds.ProbeDisconnected when !string.IsNullOrEmpty(e.Detail):
-                state.RemoveProbe(e.Detail);
+                state.RemoveProbe(e.Detail, e.Probe?.IpVersion ?? IpVersions.V4);
                 break;
             case AgentEventKinds.EndpointChanged:
                 state.CountEndpointChange();
diff --git a/backend/src/MoShiro.Backend.Application/Agents/AgentRuntime.cs b/backend/src/MoShiro.Backend.Application/Agents/AgentRuntime.cs
index 6fe7134..6471477 100644
--- a/backend/src/MoShiro.Backend.Application/Agents/AgentRuntime.cs
+++ b/backend/src/MoShiro.Backend.Application/Agents/AgentRuntime.cs
@@ -5,7 +5,7 @@ using MoShiro.Protocol;
 namespace MoShiro.Backend.Application;
 
 /// <summary>Agent 眼中的一个已连接 Probe（Agent 在事件和心跳里上报）。</summary>
-public sealed record ConnectedProbeInfo(string Id, string? Version, string? Remote, long SinceMs);
+public sealed record ConnectedProbeInfo(string Id, string? Version, string? Remote, long SinceMs, string IpVersion = IpVersions.V4);
 
 /// <summary>Agent 的运行时状态（只在内存中）：连着哪些 Probe、最近的进程内计数、端点变化次数。</summary>
 public sealed class AgentRuntimeState
@@ -19,22 +19,22 @@ public sealed class AgentRuntimeState
 
     public bool ProbeConnected => Probes.Count > 0;
 
-    public bool IsConnected(string probeId) => Probes.Any(p => p.Id == probeId);
+    public bool IsConnected(string probeId, string ipVersion = IpVersions.V4) => Probes.Any(p => p.Id == probeId && p.IpVersion == ipVersion);
 
     /// <summary>事件 <c>probe_connected</c>：事件里带着 Probe 的版本和地址；心跳里的完整快照随后会再校正一次。</summary>
     public void AddProbe(ConnectedProbeInfo info)
     {
         lock (_gate)
         {
-            Volatile.Write(ref _probes, [.. _probes.Where(p => p.Id != info.Id), info]);
+            Volatile.Write(ref _probes, [.. _probes.Where(p => p.Id != info.Id || p.IpVersion != info.IpVersion), info]);
         }
     }
 
-    public void RemoveProbe(string id)
+    public void RemoveProbe(string id, string ipVersion = IpVersions.V4)
     {
         lock (_gate)
         {
-            Volatile.Write(ref _probes, [.. _probes.Where(p => p.Id != id)]);
+            Volatile.Write(ref _probes, [.. _probes.Where(p => p.Id != id || p.IpVersion != ipVersion)]);
         }
     }
 
diff --git a/backend/src/MoShiro.Backend.Application/Agents/AgentService.cs b/backend/src/MoShiro.Backend.Application/Agents/AgentService.cs
index 5b09036..bb7f3ca 100644
--- a/backend/src/MoShiro.Backend.Application/Agents/AgentService.cs
+++ b/backend/src/MoShiro.Backend.Application/Agents/AgentService.cs
@@ -1,3 +1,5 @@
+using System.Net;
+using System.Net.Sockets;
 using System.Text.RegularExpressions;
 using Fleet.Core;
 using Fleet.Server;
@@ -49,6 +51,16 @@ public sealed partial class AgentService
         return new AgentView(agent, _gateway.IsOnline(agent.Id), state?.Probes ?? [], state?.LastHeartbeat, state?.EndpointChanges ?? 0, state?.LastHeartbeatAtMs, state?.Host);
     }
 
+    private static bool ValidHost(string host, string ipVersion)
+    {
+        if (IPAddress.TryParse(host, out IPAddress? address))
+        {
+            return !address.IsIPv4MappedToIPv6 && address.AddressFamily == (ipVersion == IpVersions.V6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork);
+        }
+
+        return host.Length <= 253 && Uri.CheckHostName(host) == UriHostNameType.Dns;
+    }
+
     public async ValueTask<Result<AgentView>> PatchAsync(NodeId id, AgentPatch patch, long? expectedRowVersion, CancellationToken ct)
     {
         var errors = new Dictionary<string, string>();
@@ -57,11 +69,16 @@ public sealed partial class AgentService
             errors["name"] = "must be 1-64 characters: letters (any language), digits, '.', '_' or '-'";
         }
 
-        if (patch.PublicHost is not null && !HostPattern().IsMatch(patch.PublicHost))
+        if (patch.PublicHost is not null && !ValidHost(patch.PublicHost, IpVersions.V4))
         {
             errors["public_host"] = "must be a host name or IP address";
         }
 
+        if (patch.Ipv6Host is not null && patch.Ipv6Host.Length > 0 && !ValidHost(patch.Ipv6Host, IpVersions.V6))
+        {
+            errors["ipv6_host"] = "must be an IPv6 address or host name; empty disables IPv6 collection";
+        }
+
         if (patch.Labels is not null && (patch.Labels.Count > 16 || patch.Labels.Any(l => l.Length is 0 or > 32)))
         {
             errors["labels"] = "at most 16 labels of 1-32 characters";
@@ -78,7 +95,7 @@ public sealed partial class AgentService
             return Result<AgentView>.Fail(error);
         }
 
-        if (patch.Name is not null || patch.PublicHost is not null)
+        if (patch.Name is not null || patch.PublicHost is not null || patch.Ipv6Host is not null)
         {
             await AfterAgentSetChangedAsync(ct);
         }
@@ -139,6 +156,7 @@ public sealed partial class AgentService
                 AgentId = agent.Id,
                 Name = agent.Name,
                 Host = agent.PublicHost,
+                Ipv6Host = agent.Ipv6Supported && agent.Ipv6Host.Length > 0 ? agent.Ipv6Host : null,
                 TcpPort = agent.ProbeTcpPort,
                 UdpPorts = [.. agent.ProbeUdpPorts],
                 Spki = Convert.ToBase64String(agent.TlsSpki),
@@ -170,7 +188,4 @@ public sealed partial class AgentService
 
     [GeneratedRegex(@"^[\p{L}\p{M}\p{N}._-]{1,64}$")]
     private static partial Regex NamePattern();
-
-    [GeneratedRegex(@"^[A-Za-z0-9.:\-\[\]]{1,253}$")]
-    private static partial Regex HostPattern();
 }
diff --git a/backend/src/MoShiro.Backend.Application/Agents/MoShiroFleetHooks.cs b/backend/src/MoShiro.Backend.Application/Agents/MoShiroFleetHooks.cs
index 492bc1f..b7dfbbe 100644
--- a/backend/src/MoShiro.Backend.Application/Agents/MoShiroFleetHooks.cs
+++ b/backend/src/MoShiro.Backend.Application/Agents/MoShiroFleetHooks.cs
@@ -99,7 +99,7 @@ public sealed class MoShiroNodeEventSink : INodeEventSink
                     _releases.RecordStatus(id, beat?.Update);
                     if (beat is not null)
                     {
-                        state.ReplaceProbes(beat.Probes.Select(p => new ConnectedProbeInfo(p.Id.Value, p.Version, p.Remote, p.SinceUtcMs)));
+                        state.ReplaceProbes(beat.Probes.Select(p => new ConnectedProbeInfo(p.Id.Value, p.Version, p.Remote, p.SinceUtcMs, p.IpVersion)));
                         foreach (ConnectedProbe p in beat.Probes)
                         {
                             _nodes.ObserveProbeInBackground(p.Id.Value, p.Remote);
@@ -196,14 +196,14 @@ public sealed class MoShiroNodeEventSink : INodeEventSink
 
         AgentRecord? before = await _agents.GetAsync(id, ct);
         string? limitsJson = meta.LocalLimits is null ? null : JsonSerializer.Serialize(meta.LocalLimits, LocalLimitsJson.Default.LocalLimits);
-        await _agents.ApplyHelloAsync(id, new AgentHello(kinds, hello.NodeVersion, limitsJson, spki is { Length: 32 } ? spki : null, meta.ProbeTcpPort, meta.ProbeUdpPorts), ct);
+        await _agents.ApplyHelloAsync(id, new AgentHello(kinds, hello.NodeVersion, limitsJson, spki is { Length: 32 } ? spki : null, meta.ProbeTcpPort, meta.ProbeUdpPorts, meta.Ipv6Supported), ct);
 
         // 端口或证书指纹变了，Probe 需要新的列表
         AgentRecord? after = await _agents.GetAsync(id, ct);
         _nodes.ObserveAgentInBackground(id.Value, after?.PublicHost, meta.Platform);
         await _releases.OfferToNodeAsync(id, ct);
         if (before is not null && after is not null
-            && (!before.TlsSpki.AsSpan().SequenceEqual(after.TlsSpki) || before.ProbeTcpPort != after.ProbeTcpPort || !before.ProbeUdpPorts.SequenceEqual(after.ProbeUdpPorts))
+            && (!before.TlsSpki.AsSpan().SequenceEqual(after.TlsSpki) || before.ProbeTcpPort != after.ProbeTcpPort || !before.ProbeUdpPorts.SequenceEqual(after.ProbeUdpPorts) || before.Ipv6Supported != after.Ipv6Supported)
             && after.Status == NodeStatus.Active)
         {
             await _service.AfterAgentSetChangedAsync(ct);
diff --git a/backend/src/MoShiro.Backend.Application/Agents/ProbeService.cs b/backend/src/MoShiro.Backend.Application/Agents/ProbeService.cs
index e47df2b..e69aca8 100644
--- a/backend/src/MoShiro.Backend.Application/Agents/ProbeService.cs
+++ b/backend/src/MoShiro.Backend.Application/Agents/ProbeService.cs
@@ -13,7 +13,7 @@ public sealed record ProbeLimits(double MaxTestMbps, long MaxTotalPps);
 public sealed record ProbeIdentityFile(ProbeId ProbeId, string PrivateKey, string Server, ProbeLimits Limits);
 
 /// <summary>某个 Probe 现在连着的一个 Agent（Agent 上报）。</summary>
-public sealed record ProbeConnection(NodeId AgentId, string AgentName, bool AgentOnline, string? Version, string? Remote, long SinceMs);
+public sealed record ProbeConnection(NodeId AgentId, string AgentName, bool AgentOnline, string? Version, string? Remote, long SinceMs, string IpVersion = IpVersions.V4);
 
 public sealed record ProbeView(ProbeRecord Probe, bool Online, IReadOnlyList<ProbeConnection> Connections)
 {
@@ -178,7 +178,7 @@ public sealed partial class ProbeService
             AgentRecord? agent = agents.FirstOrDefault(a => a.Id == agentId);
             if (agent is not null)
             {
-                connections.Add(new ProbeConnection(agentId, agent.Name, _gateway.IsOnline(agentId), info.Version, info.Remote, info.SinceMs));
+                connections.Add(new ProbeConnection(agentId, agent.Name, _gateway.IsOnline(agentId), info.Version, info.Remote, info.SinceMs, info.IpVersion));
             }
         }
 
diff --git a/backend/src/MoShiro.Backend.Application/Ingest/IngestService.cs b/backend/src/MoShiro.Backend.Application/Ingest/IngestService.cs
index 5b6b8ae..1ec486c 100644
--- a/backend/src/MoShiro.Backend.Application/Ingest/IngestService.cs
+++ b/backend/src/MoShiro.Backend.Application/Ingest/IngestService.cs
@@ -69,7 +69,8 @@ public sealed partial class IngestService
         RawChunkHeader header = chunk.Header;
         long now = _time.GetUtcNow().ToUnixTimeMilliseconds();
         string? problem =
-            header.AgentId != agent ? "agent_id does not match the authenticated node"
+            !IpVersions.IsValid(header.IpVersion) ? "unknown ip_version"
+            : header.AgentId != agent ? "agent_id does not match the authenticated node"
             : header.ChunkId.Value != msgId ? "chunk_id does not match the message id"
             : Kinds.Find(header.Kind) is null ? $"unknown kind {header.Kind}"
             : header.DurationMs is <= 0 or > MaxDurationMs ? "duration out of range"
diff --git a/backend/src/MoShiro.Backend.Application/Models/AgentModels.cs b/backend/src/MoShiro.Backend.Application/Models/AgentModels.cs
index b44c53e..1879be5 100644
--- a/backend/src/MoShiro.Backend.Application/Models/AgentModels.cs
+++ b/backend/src/MoShiro.Backend.Application/Models/AgentModels.cs
@@ -22,7 +22,9 @@ public sealed record AgentRecord(
     string? RejectedJson,
     long CreatedAtMs,
     long? LastSeenAtMs,
-    long RowVersion);
+    long RowVersion,
+    string Ipv6Host = "",
+    bool Ipv6Supported = false);
 
 /// <summary>管理员可以修改的字段（merge-patch 语义：为 null 的字段不改）。</summary>
 public sealed class AgentPatch
@@ -33,6 +35,8 @@ public sealed class AgentPatch
 
     public string? PublicHost { get; init; }
 
+    public string? Ipv6Host { get; init; }
+
     public bool? PublicVisible { get; init; }
 }
 
@@ -43,7 +47,8 @@ public sealed record AgentHello(
     string? LocalLimitsJson,
     byte[]? TlsSpki,
     int? ProbeTcpPort,
-    IReadOnlyList<int>? ProbeUdpPorts);
+    IReadOnlyList<int>? ProbeUdpPorts,
+    bool Ipv6Supported = false);
 
 /// <summary>注册之后 MoShiro 的补充：公开地址和端口。</summary>
 public sealed record AgentEnrollment(string PublicHost, int ProbeTcpPort, IReadOnlyList<int> ProbeUdpPorts, IReadOnlyList<string> Kinds);
diff --git a/backend/src/MoShiro.Backend.Application/Models/TaskAndTestModels.cs b/backend/src/MoShiro.Backend.Application/Models/TaskAndTestModels.cs
index 6502332..03936cc 100644
--- a/backend/src/MoShiro.Backend.Application/Models/TaskAndTestModels.cs
+++ b/backend/src/MoShiro.Backend.Application/Models/TaskAndTestModels.cs
@@ -30,7 +30,8 @@ public sealed record TestRecord(
     int PhaseCount,
     long RequestedAtMs,
     long? StartedAtMs,
-    long? FinishedAtMs);
+    long? FinishedAtMs,
+    string IpVersion = IpVersions.V4);
 
 /// <summary>测试结果：指标与曲线都以 JSON 保存。</summary>
 public sealed record TestResultRecord(TestId TestId, byte[] MetricsJson, byte[] SeriesJson);
diff --git a/backend/src/MoShiro.Backend.Application/Ports/StorePorts.cs b/backend/src/MoShiro.Backend.Application/Ports/StorePorts.cs
index a126798..ea9a583 100644
--- a/backend/src/MoShiro.Backend.Application/Ports/StorePorts.cs
+++ b/backend/src/MoShiro.Backend.Application/Ports/StorePorts.cs
@@ -108,6 +108,8 @@ public interface ITestStore
 
     ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, CancellationToken ct);
 
+    ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, string? ipVersion, CancellationToken ct);
+
     ValueTask<bool> UpdateStatusAsync(TestId id, string status, int? phase, string? errorCode, long nowMs, CancellationToken ct);
 
     ValueTask SetPhaseCountAsync(TestId id, int phaseCount, CancellationToken ct);
diff --git a/backend/src/MoShiro.Backend.Application/Query/Lines.cs b/backend/src/MoShiro.Backend.Application/Query/Lines.cs
index 8c07a0b..63d20a1 100644
--- a/backend/src/MoShiro.Backend.Application/Query/Lines.cs
+++ b/backend/src/MoShiro.Backend.Application/Query/Lines.cs
@@ -3,35 +3,35 @@ using MoShiro.Protocol;
 
 namespace MoShiro.Backend.Application;
 
-/// <summary>一条线路 = 一对（Agent，Probe）。存储里它的序列是 <c>line:&lt;probe_id&gt;</c>，对外的 id 是 <c>&lt;agent_id&gt;~&lt;probe_id&gt;</c>。</summary>
-public readonly record struct LineKey(NodeId Agent, ProbeId Probe)
+/// <summary>线路按（Agent，Probe，地址族）隔离。IPv4 保留 <c>agent~probe</c> 和 <c>line:probe</c>；IPv6 分别追加 <c>~ipv6</c>、<c>:ipv6</c>。</summary>
+public readonly record struct LineKey(NodeId Agent, ProbeId Probe, string IpVersion = IpVersions.V4)
 {
-    public string Series => RawChunkHeader.LinePrefix + Probe.Value;
+    public string Series => IpVersions.LineSeries(Probe.Value, IpVersion);
 
-    public string Id => Agent.Value + "~" + Probe.Value;
+    public string Id => Agent.Value + "~" + Probe.Value + (IpVersion == IpVersions.V6 ? "~ipv6" : "");
 
     public static bool TryParse(string text, out LineKey key)
     {
-        int split = text.IndexOf('~', StringComparison.Ordinal);
-        if (split <= 0 || split == text.Length - 1)
+        string[] parts = text.Split('~');
+        if (parts.Length is < 2 or > 3 || parts[0].Length == 0 || parts[1].Length == 0 || (parts.Length == 3 && parts[2] != IpVersions.V6))
         {
             key = default;
             return false;
         }
 
-        key = new LineKey(new NodeId(text[..split]), new ProbeId(text[(split + 1)..]));
+        key = new LineKey(new NodeId(parts[0]), new ProbeId(parts[1]), parts.Length == 3 ? IpVersions.V6 : IpVersions.V4);
         return true;
     }
 }
 
 /// <summary>一条线路的展示视图：Agent 的状态、Probe 记录，以及这一对现在是否连着。</summary>
-public sealed record LineView(AgentView Agent, ProbeRecord Probe)
+public sealed record LineView(AgentView Agent, ProbeRecord Probe, string IpVersion = IpVersions.V4)
 {
-    public LineKey Key => new(Agent.Agent.Id, new ProbeId(Probe.Id));
+    public LineKey Key => new(Agent.Agent.Id, new ProbeId(Probe.Id), IpVersion);
 
-    public bool Connected => Agent.Probes.Any(p => p.Id == Probe.Id);
+    public bool Connected => Agent.Probes.Any(p => p.Id == Probe.Id && p.IpVersion == IpVersion);
 
-    public ConnectedProbeInfo? Connection => Agent.Probes.FirstOrDefault(p => p.Id == Probe.Id);
+    public ConnectedProbeInfo? Connection => Agent.Probes.FirstOrDefault(p => p.Id == Probe.Id && p.IpVersion == IpVersion);
 }
 
 /// <summary>线路目录：把 id 解析成（Agent，Probe），列出所有线路。</summary>
@@ -54,7 +54,20 @@ public sealed class LineService
         IReadOnlyList<AgentView> agents = await _agents.ListAsync(ct);
         IReadOnlyList<ProbeRecord> probes = [.. (await _probes.ListAsync(ct)).Where(p => p.RevokedAtMs is null)];
         LinkSnapshot links = await _links.SnapshotAsync(ct);
-        return [.. agents.Where(include).SelectMany(a => probes.Where(p => links.IsLinked(p.Id, a.Agent.Id.Value)).Select(p => new LineView(a, p)))];
+        var result = new List<LineView>();
+        foreach (AgentView agent in agents.Where(include))
+        {
+            foreach (ProbeRecord probe in probes.Where(p => links.IsLinked(p.Id, agent.Agent.Id.Value)))
+            {
+                result.Add(new LineView(agent, probe));
+                if (agent.Agent.Ipv6Host.Length > 0)
+                {
+                    result.Add(new LineView(agent, probe, IpVersions.V6));
+                }
+            }
+        }
+
+        return result;
     }
 
     /// <summary>
@@ -64,6 +77,7 @@ public sealed class LineService
     {
         string agentPart = id;
         string? probePart = null;
+        string ipVersion = IpVersions.V4;
         if (id.Contains('~', StringComparison.Ordinal))
         {
             if (!LineKey.TryParse(id, out LineKey key))
@@ -73,6 +87,7 @@ public sealed class LineService
 
             agentPart = key.Agent.Value;
             probePart = key.Probe.Value;
+            ipVersion = key.IpVersion;
         }
 
         AgentView? agent = await _agents.GetAsync(new NodeId(agentPart), ct);
@@ -102,6 +117,6 @@ public sealed class LineService
             probe = active[0];
         }
 
-        return Result<LineView>.Ok(new LineView(agent, probe));
+        return Result<LineView>.Ok(new LineView(agent, probe, ipVersion));
     }
 }
diff --git a/backend/src/MoShiro.Backend.Application/Query/QueryService.cs b/backend/src/MoShiro.Backend.Application/Query/QueryService.cs
index d484acb..624b0a8 100644
--- a/backend/src/MoShiro.Backend.Application/Query/QueryService.cs
+++ b/backend/src/MoShiro.Backend.Application/Query/QueryService.cs
@@ -167,7 +167,7 @@ public sealed class QueryService
             }
 
             IReadOnlyDictionary<string, double> overlay = selection.WantsScores ? await TestOverlayAsync(line.Key, ct) : new Dictionary<string, double>();
-            IReadOnlyList<TestRecord> recent = await _tests.ListAsync(line.Key.Agent, line.Key.Probe, 1, ct);
+            IReadOnlyList<TestRecord> recent = await _tests.ListAsync(line.Key.Agent, line.Key.Probe, 1, line.Key.IpVersion, ct);
             result.Add(new OverviewLine(line, Summarize(merged, count, p.Plan, p.Range, selection, overlay), recent.Count > 0 ? recent[0] : null));
         }
 
@@ -372,7 +372,7 @@ public sealed class QueryService
         long cutoff = _time.GetUtcNow().ToUnixTimeMilliseconds() - (7 * Steps.Day);
         var overlay = new Dictionary<string, double>(StringComparer.Ordinal);
         var seenPlans = new HashSet<string>();
-        foreach (TestRecord test in await _tests.ListAsync(line.Agent, line.Probe, 20, ct))
+        foreach (TestRecord test in await _tests.ListAsync(line.Agent, line.Probe, 20, line.IpVersion, ct))
         {
             if (test.Status != TestStatuses.Succeeded || test.FinishedAtMs is not { } finished || finished < cutoff || !seenPlans.Add(test.Plan))
             {
diff --git a/backend/src/MoShiro.Backend.Application/Query/RowLoader.cs b/backend/src/MoShiro.Backend.Application/Query/RowLoader.cs
index 4f29b51..56304b8 100644
--- a/backend/src/MoShiro.Backend.Application/Query/RowLoader.cs
+++ b/backend/src/MoShiro.Backend.Application/Query/RowLoader.cs
@@ -139,7 +139,8 @@ public sealed class RowLoader
             IReadOnlyList<MetricRow> all = await _metrics.ReadAgentsAsync(ToLevel(plan.Source), agents, bySeries.Key, range.FromMs, range.ToMs, ct);
             foreach (IGrouping<NodeId, MetricRow> group in all.GroupBy(r => r.AgentId))
             {
-                result[new LineKey(group.Key, new ProbeId(bySeries.Key[RawChunkHeader.LinePrefix.Length..]))] = Decode([.. group]);
+                LineKey key = bySeries.First(l => l.Agent == group.Key);
+                result[key] = Decode([.. group]);
             }
         }
 
diff --git a/backend/src/MoShiro.Backend.Application/Tests/TestService.cs b/backend/src/MoShiro.Backend.Application/Tests/TestService.cs
index b0af831..ad5efa5 100644
--- a/backend/src/MoShiro.Backend.Application/Tests/TestService.cs
+++ b/backend/src/MoShiro.Backend.Application/Tests/TestService.cs
@@ -28,8 +28,16 @@ public sealed class TestService
         _time = time;
     }
 
-    public async ValueTask<Result<TestRecord>> StartAsync(NodeId agentId, ProbeId probeId, StartTestRequest request, string trigger, CancellationToken ct)
+    public ValueTask<Result<TestRecord>> StartAsync(NodeId agentId, ProbeId probeId, StartTestRequest request, string trigger, CancellationToken ct) =>
+        StartAsync(agentId, probeId, request, trigger, IpVersions.V4, ct);
+
+    public async ValueTask<Result<TestRecord>> StartAsync(NodeId agentId, ProbeId probeId, StartTestRequest request, string trigger, string ipVersion, CancellationToken ct)
     {
+        if (!IpVersions.IsValid(ipVersion))
+        {
+            return ValidationError.Fail<TestRecord>("ip_version", "must be ipv4 or ipv6");
+        }
+
         PlanSpec? plan = Plans.Find(request.Plan);
         if (plan is null)
         {
@@ -47,6 +55,11 @@ public sealed class TestService
             return Result<TestRecord>.Fail(MoShiroErrors.AgentNotActive, "agent is not active");
         }
 
+        if (ipVersion == IpVersions.V6 && !agent.Ipv6Supported)
+        {
+            return Result<TestRecord>.Fail(FleetErrors.Unsupported, "this agent has not enabled IPv6 collection");
+        }
+
         // Agent 在 hello 里声明了它支持的采集方法：方案里有它不支持的就不下发（否则要等到阶段开始才失败）
         string? unsupported = plan.Phases.Select(p => p.Kind).FirstOrDefault(kind => !agent.Kinds.Contains(kind));
         if (unsupported is not null)
@@ -65,7 +78,7 @@ public sealed class TestService
             return Result<TestRecord>.Fail(MoShiroErrors.AgentOffline, "agent is offline");
         }
 
-        if (!(_runtime.TryGet(agentId, out AgentRuntimeState? state) && state.IsConnected(probeId.Value)))
+        if (!(_runtime.TryGet(agentId, out AgentRuntimeState? state) && state.IsConnected(probeId.Value, ipVersion)))
         {
             return Result<TestRecord>.Fail(MoShiroErrors.ProbeOffline, $"probe {probeId.Value} has no session with this agent");
         }
@@ -78,10 +91,10 @@ public sealed class TestService
         var testId = new TestId(Ulid.NewPrefixed(TestId.Prefix, _time));
         long now = _time.GetUtcNow().ToUnixTimeMilliseconds();
         string paramsJson = request.Params is null ? "{}" : JsonSerializer.Serialize(new Dictionary<string, JsonElement>(request.Params), TestJson.Default.ParamMap);
-        var record = new TestRecord(testId, agentId, probeId, plan.Id, paramsJson, trigger, TestStatuses.Queued, null, null, phaseList.Count, now, null, null);
+        var record = new TestRecord(testId, agentId, probeId, plan.Id, paramsJson, trigger, TestStatuses.Queued, null, null, phaseList.Count, now, null, null, ipVersion);
         await _tests.CreateAsync(record, ct);
 
-        Result<bool> sent = await _gateway.RunTestAsync(agentId, new TestRunParams { TestId = testId, ProbeId = probeId, Plan = plan.Id, Phases = phaseList }, ct);
+        Result<bool> sent = await _gateway.RunTestAsync(agentId, new TestRunParams { TestId = testId, ProbeId = probeId, IpVersion = ipVersion, Plan = plan.Id, Phases = phaseList }, ct);
         if (!sent.TryGet(out _, out FleetError? sendError))
         {
             await _tests.UpdateStatusAsync(testId, TestStatuses.Failed, null, sendError.Code.Value, now, ct);
@@ -149,6 +162,8 @@ public sealed class TestService
 
     public ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, CancellationToken ct) => _tests.ListAsync(agentId, probeId, limit, ct);
 
+    public ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, string? ipVersion, CancellationToken ct) => _tests.ListAsync(agentId, probeId, limit, ipVersion, ct);
+
     public static TestResultView ToView(TestResultRecord stored)
     {
         StoredTestMetrics metrics = JsonSerializer.Deserialize(stored.MetricsJson, TestJson.Default.StoredTestMetrics) ?? new StoredTestMetrics();
diff --git a/backend/src/MoShiro.Backend.Storage.Sqlite/Schema.cs b/backend/src/MoShiro.Backend.Storage.Sqlite/Schema.cs
index 69b20f4..625140d 100644
--- a/backend/src/MoShiro.Backend.Storage.Sqlite/Schema.cs
+++ b/backend/src/MoShiro.Backend.Storage.Sqlite/Schema.cs
@@ -5,7 +5,7 @@ namespace MoShiro.Backend.Storage.Sqlite;
 /// <summary>表结构。版本记录在 <c>PRAGMA user_version</c>；以后的迁移是按版本号追加的内置 SQL。</summary>
 internal static class Schema
 {
-    public const int CurrentVersion = 5;
+    public const int CurrentVersion = 6;
 
     public static void Migrate(SqliteConnection connection)
     {
@@ -90,6 +90,17 @@ internal static class Schema
             connection.Exec("PRAGMA user_version = 5");
             transaction.Commit();
         }
+
+        if (version < 6)
+        {
+            using SqliteTransaction transaction = connection.BeginTransaction();
+            connection.Exec("ALTER TABLE agents ADD COLUMN ipv6_host TEXT NOT NULL DEFAULT ''");
+            connection.Exec("ALTER TABLE agents ADD COLUMN ipv6_supported INTEGER NOT NULL DEFAULT 0");
+            connection.Exec("ALTER TABLE tests ADD COLUMN ip_version TEXT NOT NULL DEFAULT 'ipv4'");
+            connection.Exec("CREATE INDEX ix_tests_path ON tests (agent_id, probe_id, ip_version, requested_at)");
+            connection.Exec("PRAGMA user_version = 6");
+            transaction.Commit();
+        }
     }
 
     /// <summary>
diff --git a/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteAgentStore.cs b/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteAgentStore.cs
index 1774315..e3e8d8f 100644
--- a/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteAgentStore.cs
+++ b/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteAgentStore.cs
@@ -14,7 +14,7 @@ public sealed class SqliteAgentStore : IAgentStore, IFleetStore
 {
     private const string AgentColumns =
         "id, name, status, pubkey, tls_spki, public_host, probe_tcp_port, probe_udp_ports, labels, public_visible, kinds, agent_version, local_limits, " +
-        "task_version, applied_task_version, rejected, created_at, last_seen_at, row_version";
+        "task_version, applied_task_version, rejected, created_at, last_seen_at, row_version, ipv6_host, ipv6_supported";
 
     private readonly SqliteDatabase _db;
 
@@ -61,10 +61,10 @@ public sealed class SqliteAgentStore : IAgentStore, IFleetStore
             }
 
             c.Exec(
-                "UPDATE agents SET name = @name, labels = @labels, public_host = @host, public_visible = @visible, row_version = row_version + 1 WHERE id = @id",
+                "UPDATE agents SET name = @name, labels = @labels, public_host = @host, ipv6_host = @v6, public_visible = @visible, row_version = row_version + 1 WHERE id = @id",
                 ("@id", id.Value), ("@name", patch.Name ?? current.Name),
                 ("@labels", StorageJson.ToJson(patch.Labels ?? current.Labels)),
-                ("@host", patch.PublicHost ?? current.PublicHost), ("@visible", (patch.PublicVisible ?? current.PublicVisible) ? 1 : 0));
+                ("@host", patch.PublicHost ?? current.PublicHost), ("@v6", patch.Ipv6Host ?? current.Ipv6Host), ("@visible", (patch.PublicVisible ?? current.PublicVisible) ? 1 : 0));
             return Result<AgentRecord>.Ok(GetInternal(c, id)!);
         }, ct);
 
@@ -117,9 +117,9 @@ public sealed class SqliteAgentStore : IAgentStore, IFleetStore
         {
             c.Exec(
                 "UPDATE agents SET kinds = @kinds, agent_version = @version, local_limits = COALESCE(@limits, local_limits), tls_spki = COALESCE(@spki, tls_spki), " +
-                "probe_tcp_port = COALESCE(@tcp, probe_tcp_port), probe_udp_ports = COALESCE(@udp, probe_udp_ports), row_version = row_version + 1 WHERE id = @id",
+                "probe_tcp_port = COALESCE(@tcp, probe_tcp_port), probe_udp_ports = COALESCE(@udp, probe_udp_ports), ipv6_supported = @v6, row_version = row_version + 1 WHERE id = @id",
                 ("@id", id.Value), ("@kinds", StorageJson.ToJson(hello.Kinds)), ("@version", hello.AgentVersion), ("@limits", hello.LocalLimitsJson),
-                ("@spki", hello.TlsSpki), ("@tcp", hello.ProbeTcpPort), ("@udp", hello.ProbeUdpPorts is null ? null : StorageJson.ToJson(hello.ProbeUdpPorts)));
+                ("@spki", hello.TlsSpki), ("@tcp", hello.ProbeTcpPort), ("@udp", hello.ProbeUdpPorts is null ? null : StorageJson.ToJson(hello.ProbeUdpPorts)), ("@v6", hello.Ipv6Supported ? 1 : 0));
         }, ct);
 
     public ValueTask SetTaskVersionAsync(NodeId id, long version, string taskHash, CancellationToken ct) =>
@@ -217,7 +217,9 @@ public sealed class SqliteAgentStore : IAgentStore, IFleetStore
         r.NullableString(15),
         r.GetInt64(16),
         r.NullableLong(17),
-        r.GetInt64(18));
+        r.GetInt64(18),
+        r.GetString(19),
+        r.GetInt64(20) != 0);
 
     private static NodeRecord ToNode(AgentRecord a, string? metaJson) =>
         new(a.Id, a.Name, a.Status, a.PublicKey, a.TlsSpki, a.Labels, metaJson, a.AgentVersion, a.CreatedAtMs, a.LastSeenAtMs);
diff --git a/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteTestStore.cs b/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteTestStore.cs
index b763b41..eba95d9 100644
--- a/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteTestStore.cs
+++ b/backend/src/MoShiro.Backend.Storage.Sqlite/SqliteTestStore.cs
@@ -7,7 +7,7 @@ namespace MoShiro.Backend.Storage.Sqlite;
 
 public sealed class SqliteTestStore : ITestStore
 {
-    private const string Columns = "id, agent_id, plan, params, trigger, status, error_code, phase, phase_count, requested_at, started_at, finished_at, probe_id";
+    private const string Columns = "id, agent_id, plan, params, trigger, status, error_code, phase, phase_count, requested_at, started_at, finished_at, probe_id, ip_version";
 
     private readonly SqliteDatabase _db;
 
@@ -19,19 +19,22 @@ public sealed class SqliteTestStore : ITestStore
     public ValueTask CreateAsync(TestRecord test, CancellationToken ct) =>
         _db.ExecuteAsync(
             c => c.Exec(
-                "INSERT INTO tests (id, agent_id, probe_id, plan, params, trigger, status, error_code, phase, phase_count, requested_at) VALUES (@id, @agent, @probe, @plan, @params, @trigger, @status, @err, @phase, @count, @at)",
+                "INSERT INTO tests (id, agent_id, probe_id, plan, params, trigger, status, error_code, phase, phase_count, requested_at, ip_version) VALUES (@id, @agent, @probe, @plan, @params, @trigger, @status, @err, @phase, @count, @at, @ip)",
                 ("@id", test.Id.Value), ("@agent", test.AgentId.Value), ("@probe", test.ProbeId.Value), ("@plan", test.Plan), ("@params", test.ParamsJson), ("@trigger", test.Trigger),
-                ("@status", test.Status), ("@err", test.ErrorCode), ("@phase", test.Phase), ("@count", test.PhaseCount), ("@at", test.RequestedAtMs)),
+                ("@status", test.Status), ("@err", test.ErrorCode), ("@phase", test.Phase), ("@count", test.PhaseCount), ("@at", test.RequestedAtMs), ("@ip", test.IpVersion)),
             ct);
 
     public ValueTask<TestRecord?> GetAsync(TestId id, CancellationToken ct) =>
         _db.ReadAsync(c => c.QueryOne($"SELECT {Columns} FROM tests WHERE id = @id", Read, ("@id", id.Value)), ct);
 
     public ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, CancellationToken ct) =>
+        ListAsync(agentId, probeId, limit, null, ct);
+
+    public ValueTask<IReadOnlyList<TestRecord>> ListAsync(NodeId? agentId, ProbeId? probeId, int limit, string? ipVersion, CancellationToken ct) =>
         _db.ReadAsync<IReadOnlyList<TestRecord>>(
             c => c.Query(
-                $"SELECT {Columns} FROM tests WHERE (@agent IS NULL OR agent_id = @agent) AND (@probe IS NULL OR probe_id = @probe) ORDER BY requested_at DESC, id DESC LIMIT @limit",
-                Read, ("@agent", agentId?.Value), ("@probe", probeId?.Value), ("@limit", limit)),
+                $"SELECT {Columns} FROM tests WHERE (@agent IS NULL OR agent_id = @agent) AND (@probe IS NULL OR probe_id = @probe) AND (@ip IS NULL OR ip_version = @ip) ORDER BY requested_at DESC, id DESC LIMIT @limit",
+                Read, ("@agent", agentId?.Value), ("@probe", probeId?.Value), ("@limit", limit), ("@ip", ipVersion)),
             ct);
 
     public ValueTask<bool> UpdateStatusAsync(TestId id, string status, int? phase, string? errorCode, long nowMs, CancellationToken ct) =>
@@ -88,5 +91,6 @@ public sealed class SqliteTestStore : ITestStore
         r.GetInt32(8),
         r.GetInt64(9),
         r.NullableLong(10),
-        r.NullableLong(11));
+        r.NullableLong(11),
+        r.GetString(13));
 }
diff --git a/backend/tests/MoShiro.Backend.Tests/HostTests.cs b/backend/tests/MoShiro.Backend.Tests/HostTests.cs
index ca4ea9b..75ccee3 100644
--- a/backend/tests/MoShiro.Backend.Tests/HostTests.cs
+++ b/backend/tests/MoShiro.Backend.Tests/HostTests.cs
@@ -30,7 +30,7 @@ public sealed class HostSamplerTests
         var time = new Microsoft.Extensions.Time.Testing.FakeTimeProvider();
         string stat = Stat1;
         string dev = Dev1;
-        var sampler = new HostSampler(time, path => path switch { "/proc/stat" => stat, "/proc/net/dev" => dev, "/proc/uptime" => "100.0 1.0", _ => null }, () => (1000, 250), procRoot: "/proc", sysRoot: "/sys");
+        var sampler = new HostSampler(time, path => path.Replace('\\', '/') switch { "/proc/stat" => stat, "/proc/net/dev" => dev, "/proc/uptime" => "100.0 1.0", _ => null }, () => (1000, 250), procRoot: "/proc", sysRoot: "/sys");
         HostSnapshot first = sampler.Sample();
         Assert.Null(first.CpuPercent); // 第一次没有基线
         Assert.Null(first.NetRxBps);
@@ -53,6 +53,7 @@ public sealed class HostSamplerTests
         var reads = new List<string>();
         var sampler = new HostSampler(TimeProvider.System, path =>
         {
+            path = path.Replace('\\', '/'); // 测试里的 /proc 格式统一用斜杠，兼容 Windows 的 Path.Combine
             reads.Add(path);
             return path switch
             {
diff --git a/backend/tests/MoShiro.Backend.Tests/Ipv6Tests.cs b/backend/tests/MoShiro.Backend.Tests/Ipv6Tests.cs
new file mode 100644
index 0000000..9961347
--- /dev/null
+++ b/backend/tests/MoShiro.Backend.Tests/Ipv6Tests.cs
@@ -0,0 +1,165 @@
+using System.Net;
+using System.Net.Sockets;
+using System.Text.Json.Nodes;
+using Microsoft.Extensions.DependencyInjection;
+using MoShiro.Backend.Application;
+using MoShiro.Protocol;
+using MoShiro.TestSupport;
+
+namespace MoShiro.Backend.Tests;
+
+/// <summary>真实双栈回环：同一身份的两种会话、原始块、查询与测试结果必须各自独立。</summary>
+[Collection("probe-e2e")]
+public sealed class Ipv6Tests
+{
+    private readonly BackendFixture _backend;
+
+    public Ipv6Tests(BackendFixture backend)
+    {
+        _backend = backend;
+    }
+
+    [Fact]
+    public async Task Queries_DifferentFamilyLoss_RemainsIndependentInHotPersistedAndCompareViews()
+    {
+        await using AgentSimulator agent = await _backend.ConnectAgentAsync();
+        long start = ((TimeProvider.System.GetUtcNow().ToUnixTimeMilliseconds() / 60_000) - 4) * 60_000;
+        for (int k = 0; k < 6; k++)
+        {
+            foreach (string version in new[] { IpVersions.V4, IpVersions.V6 })
+            {
+                RawChunk chunk = ChunkFactory.Echo(agent.NodeId, "udp_echo", start + k * 10_000, 100, 100,
+                    i => new EchoPacket(false, version == IpVersions.V6 && i % 2 == 0, 20_000, 20_000));
+                chunk.Header.ProbeId = new ProbeId(_backend.DefaultProbeId);
+                chunk.Header.IpVersion = version;
+                Assert.True(await agent.SendChunkAsync(chunk));
+            }
+        }
+
+        string range = "from=" + DateTimeOffset.FromUnixTimeMilliseconds(start).UtcDateTime.ToString("yyyy-MM-ddTHH:mm:ss.fffZ")
+            + "&to=" + DateTimeOffset.FromUnixTimeMilliseconds(start + 60_000).UtcDateTime.ToString("yyyy-MM-ddTHH:mm:ss.fffZ");
+        string v4 = _backend.Line(agent.NodeId);
+        string v6 = v4 + "~ipv6";
+        foreach (string step in new[] { "1s", "10s", "1m" })
+        {
+            foreach ((string line, double loss) in new[] { (v4, 0.0), (v6, 50.0) })
+            {
+                JsonNode series = null!;
+                await BackendFixture.EventuallyAsync(async () =>
+                {
+                    series = await _backend.GetJsonAsync(_backend.Admin, $"/api/public/lines/{line}/series?{range}&step={step}&preset=udp");
+                    return series["summary"]!["samples"]!["udp_echo"]?.GetValue<long>() == 600;
+                });
+                Assert.Equal(loss, series["summary"]!["metrics"]!["loss.total"]!.GetValue<double>(), 6);
+            }
+        }
+
+        JsonNode compare = await _backend.GetJsonAsync(_backend.Admin, $"/api/public/compare?lines={v4},{v6}&metric=loss.total&step=1m&{range}");
+        Assert.Equal(0, compare["summary"]![v4]!.GetValue<double>());
+        Assert.Equal(50, compare["summary"]![v6]!.GetValue<double>());
+
+        await using SseClient live = await SseClient.ConnectAsync(_backend.Admin, $"/api/public/live?topics=series:{v6}:10s:udp");
+        SseEvent snapshot = await live.WaitForAsync(e => e.Name == "series" && e.Data?["line_id"]?.GetValue<string>() == v6);
+        Assert.Equal("ipv6", snapshot.Data!["ip_version"]!.GetValue<string>());
+    }
+
+    [Fact]
+    public async Task Ipv6Configuration_RejectsWrongFamily_AndDoesNotArrangeIpv6ForALegacyAgent()
+    {
+        await using AgentSimulator agent = await _backend.ConnectAgentAsync();
+        using HttpResponseMessage invalid = await _backend.Admin.PatchAsync("/api/admin/agents/" + agent.NodeId.Value,
+            BackendFixture.Json(new JsonObject { ["ipv6_host"] = "127.0.0.1" }));
+        Assert.Equal(HttpStatusCode.BadRequest, invalid.StatusCode);
+        Assert.Contains("ipv6_host", await invalid.Content.ReadAsStringAsync(), StringComparison.Ordinal);
+        using HttpResponseMessage valid = await _backend.Admin.PatchAsync("/api/admin/agents/" + agent.NodeId.Value,
+            BackendFixture.Json(new JsonObject { ["ipv6_host"] = "::1" }));
+        Assert.True(valid.IsSuccessStatusCode);
+        ProbeAgentList endpoints = await _backend.Services.GetRequiredService<AgentService>().ProbeAgentsAsync(_backend.DefaultProbeId, default);
+        Assert.Null(Assert.Single(endpoints.Agents, a => a.AgentId == agent.NodeId).Ipv6Host);
+        JsonNode identity = await _backend.GetJsonAsync(_backend.Admin, "/api/admin/agents/" + agent.NodeId.Value);
+        Assert.Equal("::1", identity["ipv6_host"]!.GetValue<string>());
+        Assert.False(identity["ipv6_supported"]!.GetValue<bool>());
+    }
+
+    [Fact]
+    public async Task DualStack_CollectsBothFamilies_DisablingIpv6KeepsIpv4Running()
+    {
+        Assert.SkipUnless(Socket.OSSupportsIPv6, "IPv6 sockets are unavailable on this host");
+        await using AgentHarness agent = await AgentHarness.StartAsync(_backend, c => c.Listen.Bind = "::");
+        await agent.OverrideLineTasksAsync(rateHz: 30);
+        using HttpResponseMessage configured = await _backend.Admin.PatchAsync("/api/admin/agents/" + agent.Id,
+            BackendFixture.Json(new JsonObject { ["public_host"] = "127.0.0.1", ["ipv6_host"] = "::1" }));
+        Assert.True(configured.IsSuccessStatusCode, await configured.Content.ReadAsStringAsync());
+        await using ProbeHarness probe = await ProbeHarness.StartAsync(_backend);
+        await BackendFixture.EventuallyAsync(() => Task.FromResult(probe.App.IsConnected(agent.Id) && probe.App.IsConnected(agent.Id, IpVersions.V6)));
+        await BackendFixture.EventuallyAsync(async () =>
+        {
+            JsonNode raw = await _backend.GetJsonAsync(_backend.Admin, "/api/admin/raw/chunks?agent_id=" + agent.Id);
+            return new[] { "line:" + probe.ProbeId, "line:" + probe.ProbeId + ":ipv6" }.All(series =>
+                new[] { "udp_echo", "tcp_echo" }.All(kind => raw["items"]!.AsArray().Any(c => c!["series"]!.GetValue<string>() == series && c["kind"]!.GetValue<string>() == kind)));
+        }, TimeSpan.FromSeconds(45));
+
+        string v4 = agent.Id + "~" + probe.ProbeId;
+        string v6 = v4 + "~ipv6";
+        foreach (string step in new[] { "1s", "10s" })
+        {
+            foreach ((string line, string family) in new[] { (v4, IpVersions.V4), (v6, IpVersions.V6) })
+            {
+                JsonNode series = await _backend.GetJsonAsync(_backend.Admin, $"/api/public/lines/{line}/series?range=1m&step={step}&preset=udp,tcp");
+                Assert.Equal(family, series["ip_version"]!.GetValue<string>());
+                Assert.True(series["summary"]!["samples"]!["udp_echo"]!.GetValue<long>() > 0, series.ToJsonString());
+                Assert.True(series["summary"]!["samples"]!["tcp_echo"]!.GetValue<long>() > 0, series.ToJsonString());
+            }
+        }
+
+        JsonNode overview = await _backend.GetJsonAsync(_backend.Admin, "/api/public/overview?range=1m&ip_version=ipv6");
+        Assert.Contains(overview["lines"]!.AsArray(), l => l!["id"]!.GetValue<string>() == v6);
+        Assert.All(overview["lines"]!.AsArray(), l => Assert.Equal("ipv6", l!["ip_version"]!.GetValue<string>()));
+
+        var ipv4Connection = probe.App.Connection(agent.Id);
+        long previous = agent.App.Counters.Fragments;
+        using HttpResponseMessage disabled = await _backend.Admin.PatchAsync("/api/admin/agents/" + agent.Id, BackendFixture.Json(new JsonObject { ["ipv6_host"] = "" }));
+        Assert.True(disabled.IsSuccessStatusCode);
+        await BackendFixture.EventuallyAsync(() => Task.FromResult(probe.App.Connection(agent.Id, IpVersions.V6) is null));
+        Assert.Same(ipv4Connection, probe.App.Connection(agent.Id));
+        Assert.True(probe.App.IsConnected(agent.Id));
+        await BackendFixture.EventuallyAsync(() => Task.FromResult(agent.App.Counters.Fragments > previous), TimeSpan.FromSeconds(20));
+        Assert.Equal(0, agent.App.Counters.FragmentsDiscarded);
+    }
+
+    [Theory]
+    [InlineData("hy2_ladder")]
+    [InlineData("reality_session")]
+    public async Task Ipv6Test_UsesIpv6Session_AndDoesNotAppearInIpv4History(string plan)
+    {
+        Assert.SkipUnless(Socket.OSSupportsIPv6, "IPv6 sockets are unavailable on this host");
+        await using AgentHarness agent = await AgentHarness.StartAsync(_backend, c => c.Listen.Bind = "::");
+        await agent.OverrideLineTasksAsync();
+        using HttpResponseMessage configured = await _backend.Admin.PatchAsync("/api/admin/agents/" + agent.Id,
+            BackendFixture.Json(new JsonObject { ["ipv6_host"] = "::1" }));
+        Assert.True(configured.IsSuccessStatusCode);
+        await using ProbeHarness probe = await ProbeHarness.StartAsync(_backend);
+        string v4 = agent.Id + "~" + probe.ProbeId;
+        string v6 = v4 + "~ipv6";
+        await BackendFixture.EventuallyAsync(async () =>
+            (await _backend.GetJsonAsync(_backend.Admin, "/api/admin/agents/" + agent.Id))["probes"]!.AsArray()
+                .Any(p => p!["probe_id"]!.GetValue<string>() == probe.ProbeId && p["ip_version"]!.GetValue<string>() == "ipv6"));
+        var parameters = plan == "hy2_ladder" ? new JsonObject { ["mbps"] = 1, ["duration_s"] = 1 } : new JsonObject { ["duration_s"] = 1 };
+        using HttpResponseMessage accepted = await _backend.Admin.PostAsync($"/api/admin/lines/{v6}/tests", BackendFixture.Json(new JsonObject { ["plan"] = plan, ["params"] = parameters }));
+        Assert.Equal(HttpStatusCode.Accepted, accepted.StatusCode);
+        string id = JsonNode.Parse(await accepted.Content.ReadAsStringAsync())!["id"]!.GetValue<string>();
+        JsonNode result = null!;
+        await BackendFixture.EventuallyAsync(async () =>
+        {
+            result = await _backend.GetJsonAsync(_backend.Admin, "/api/public/tests/" + id);
+            return result["status"]!.GetValue<string>() is "failed" or "aborted" || result["result"] is not null;
+        }, TimeSpan.FromSeconds(100));
+        Assert.Equal("succeeded", result["status"]!.GetValue<string>());
+        Assert.Equal("ipv6", result["ip_version"]!.GetValue<string>());
+        Assert.NotNull(result["result"]);
+        JsonNode history = await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/lines/{v4}/tests");
+        Assert.Empty(history["items"]!.AsArray());
+        JsonNode v6History = await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/lines/{v6}/tests");
+        Assert.Contains(v6History["items"]!.AsArray(), t => t!["id"]!.GetValue<string>() == id);
+    }
+}
diff --git a/docs/api.md b/docs/api.md
index 6adfeb5..8449434 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -4,6 +4,14 @@
 
 ## 1. 分层
 
+### IPv4 / IPv6
+
+- `PATCH /api/admin/agents/{id}` 新增可选 `ipv6_host`：IPv6 地址或域名；空字符串关闭 IPv6，缺省或 null 不修改。原 `public_host` 用于 IPv4。
+- `GET /api/public/overview` 新增可选 `ip_version=ipv4|ipv6`，缺省 IPv4。SSE `/api/public/live` 的同名参数选择 overview 主题的地址族；series 主题仍按线路 id 定位。
+- IPv4 线路 id 保持 `agent~probe`，IPv6 为 `agent~probe~ipv6`。series、distribution、heatmap、compare 和管理端测试端点共用这个标识。测试记录与评分叠加独立。
+- 线路、时序、测试和连接 DTO 新增 `ip_version`；管理端 Agent DTO 新增 `ipv6_host`、`ipv6_supported`；线路详情新增 `ipv6_available`（是否配置了 IPv6 地址）。公开 DTO 不包含任一种 IP 地址。
+- API v1 采用新增字段和可选参数，现有 IPv4 请求及历史链接继续有效。前端类型从 OpenAPI 重新生成。
+
 ```text
 /api/public/*     只读。站点设为公开时匿名可访问，设为私有时需要登录或只读令牌；
                   public_visible = false 的 Agent 对匿名访客隐藏
diff --git a/docs/deployment.md b/docs/deployment.md
index 4a7631d..f20281f 100644
--- a/docs/deployment.md
+++ b/docs/deployment.md
@@ -4,6 +4,14 @@
 
 ## 1. 构建与打包
 
+### 启用 IPv6 测量
+
+升级 Backend、Agent、Probe 后，在管理端的 Agent 编辑页保留 IPv4 地址，并填写 IPv6 地址或带 AAAA 记录的域名。未填写 IPv6 地址的 VPS 只采集 IPv4；Probe 没有 IPv6 路由或 IPv6 连接失败时，IPv4 会话继续工作。
+
+Agent 的新默认监听地址为 `::`（双栈）；现有 `agent.json` 如果显式配置了 `0.0.0.0`，需要在宿主机改为 `::` 并重启节点。系统不支持 IPv6 套接字时，新默认值退回 IPv4 监听。防火墙需允许 IPv6 的 `7443/tcp`、`7443/udp`、`7444/tcp`（自定义端口时用实际端口）；容器推荐宿主网络。管理端的「IPv6 监听」显示节点实际是否启用。
+
+原来的 SQLite 数据库自动迁移，旧原始块、指标和测试结果继续属于 IPv4。先升级 Backend，再升级节点，最后填写 IPv6 地址；旧 Agent 不会上报 IPv6 支持，Backend 不会给它安排第二条会话。
+
 ```text
 scripts/publish.sh <agent|probe|backend|fleet-enroll> <rid>      → backend/artifacts/publish/<project>/<rid>/
 scripts/package.sh <agent|probe> <rid>                           → backend/artifacts/packages/moshiro-<role>-<version>-<rid>.tar.gz（附 .sha256）
diff --git a/docs/measurement.md b/docs/measurement.md
index f8f7cd6..0a56449 100644
--- a/docs/measurement.md
+++ b/docs/measurement.md
@@ -8,6 +8,8 @@
 
 ## 2. 任务模型
 
+同一个 Probe 与 Agent 的 IPv4、IPv6 路径并行执行相同的持续线路任务模板，各自记录、上传、分析。IPv6 只在管理端配置了地址且 Agent 上报支持时建立；两端的控制和数据通道固定使用同一地址族。按需测试通过所选线路 id 指定地址族，重负载并发限制仍按 Agent 和 Probe 的本机策略执行。两个地址族分别使用有界发件箱（Probe 每路径 8 MB，Agent 的共同上传队列 64 MB）。
+
 ```text
 Task = { id, scope, kind, target, params, schedule, enabled }
 
diff --git a/docs/protocol.md b/docs/protocol.md
index 880285f..48f3a10 100644
--- a/docs/protocol.md
+++ b/docs/protocol.md
@@ -94,6 +94,17 @@ Probe 只记录自己一侧的列，Agent 在数据面记录另一侧，由 Agen
 
 ## 4. 版本演进
 
+### IPv4 / IPv6 路径
+
+- 一个 Probe 与 Agent 可以同时建立 IPv4、IPv6 两个会话，共用身份公钥，各自使用独立的会话密钥、流、时钟估计与发件箱。重连只替换同地址族的会话。
+- `probe_agents.agents[]` 保留 `host`（IPv4 地址或 A 记录域名），新增可选 `ipv6_host`（IPv6 地址或 AAAA 记录域名）。未配置时不建立 IPv6 会话；Probe 按地址族解析，不跨地址族回退。
+- Agent 在 hello 的元数据里上报 `ipv6_supported`，只在本机监听 IPv6 时为 true。Backend 只向支持它的 Agent 安排 IPv6 路径，旧 Agent 缺省为 false。
+- `ConnectedProbe`、`TestRunParams` 和 RawChunk 块头新增 `ip_version`，取值 `ipv4` / `ipv6`，缺省 `ipv4`。Agent 合并列块时以认证过的控制会话地址族为准，覆盖 Probe 上报的值。
+- IPv4 的线路 id `agent~probe`、序列 `line:probe` 保持不变；IPv6 使用 `agent~probe~ipv6`、`line:probe:ipv6`。指标、重算、SSE 和测试结果按路径隔离。
+- 本次是 JSON 字段扩展，二进制包、列编码和容器布局没有变化，协议与 `container_version` 保持原版本。双栈采集需要升级 Agent 和 Probe；旧节点继续提供 IPv4。
+
+### 通用规则
+
 - Fleet 层的兼容规则见 [../backend/fleet/README.md](../backend/fleet/README.md)。
 - `moshiro.*` 方法：新增方法或可选字段不需要升级版本，接收方忽略未知字段。
 - RawChunk：块头自描述，新增列或新增 Kind 不需要升级 `container_version`；只有容器格式变化时才升级。
diff --git a/web/README.md b/web/README.md
index 448b3c9..ec8e0c3 100644
--- a/web/README.md
+++ b/web/README.md
@@ -22,6 +22,7 @@ npm run lint:css               # 颜色只能写在 shared/theme/tokens.css，
 连别的后端（本机跑前端、连线上的）：登录页左边选后端（这个页面自己所在的、保存过的，或者「添加后端」），右边都是用户名和密码；添加后端填地址、用户名、密码，登录成功才保存。跨域用不了 Cookie，所以登录时后端会返回会话令牌（`return_session`），前端存在浏览器里、之后每个请求带上，12 小时过期、退出登录即作废；用户看不到也不需要管它。后端需要放行这个页面的来源（`MoShiro__CorsOrigins`）。展示端和管理端侧栏的插头图标是同一个切换器。
 
 约定：
+- 总览、线路详情、对比和管理端按需测试均可切换 IPv4 / IPv6；查询和测试结果独立。管理端 Agent 编辑页分别配置 IPv4、IPv6 地址，IPv6 留空只采 IPv4。展示端只显示地址族，不显示 IP。
 - 展示端能拿到的主机数据只有汇总的数字（CPU、内存、磁盘占用，网卡累计流量与瞬时网速，运行时长），**没有 CPU 型号、主机名、网卡名，也没有任何 IP**——后端的公开接口不返回它们，Agent 也根本不采集。展示端不显示 Probe 的版本和来源地址（这些只在管理端）。
 - 线路详情页：先选**哪一天**（前一天 / 后一天 / 日期选择，URL 的 `day=YYYY-MM-DD`），下面是这一天的丢包缩略图，上面有可拖动的选区（拖空白处新建、拖两边调长短、拖中间平移；URL 的 `at=起_止`，单位是从选中那天 0 点算起的分钟，可以是负数或超过 1440）。缩略图的**刻度**缺省是 48 小时（连续两天，选区可以跨零点，比如晚高峰 20:00 到凌晨 02:00），也可以切成 24 小时（只看一天；URL 的 `span=24`，选区跨零点时自动用 48 小时）。刻度下方是**选区长度**：30 分钟、1 小时、3 小时、6 小时、12 小时、整天，点一下把选区设成这么长——今天且选区到现在为止的，继续看「最近一段」（实时刷新），否则保持选区的起点往后取。刻度上每小时一根短线，48 小时刻度每 3 小时标一个钟点（24 小时刻度每 2 小时），零点标日期；鼠标移到缩略图上会标出那个位置的时间；点一下空白处或者刻度下面的钟点：离那里近的端点（左端或右端）贴过去，另一个端点不动。鼠标停在轴上或刻度上时，会动的那个端点变色，它到目标位置之间染色：扩大是橙色，收缩是灰色。往日默认是整天；「整天」是本地时区的自然日。时间的文字不写「次日」，跨零点两头都写日期（2026年10月5日 21:06 – 2026年10月6日 02:31）。
 - 图表上方有 **EWMA 平滑**开关（关、轻 α=0.3、中 α=0.1、重 α=0.03；URL 的 `ewma=low|mid|high`）：开了之后每条线画成指数加权移动平均，原始数据以淡线垫在后面，缺口处断开；只在浏览器里算，不影响汇总的指标数字。
diff --git a/web/admin/src/pages/AgentDetail.tsx b/web/admin/src/pages/AgentDetail.tsx
index 92d25bc..1cdaf10 100644
--- a/web/admin/src/pages/AgentDetail.tsx
+++ b/web/admin/src/pages/AgentDetail.tsx
@@ -13,6 +13,7 @@ function EditDialog({ agent, onClose, onSaved }: { agent: AgentDto; onClose: ()
   const [name, setName] = useState(agent.name)
   const [labels, setLabels] = useState(agent.labels.join(', '))
   const [host, setHost] = useState(agent.public_host)
+  const [ipv6Host, setIpv6Host] = useState(agent.ipv6_host ?? '')
   const [visible, setVisible] = useState(agent.public_visible)
   return (
     <Dialog
@@ -29,7 +30,7 @@ function EditDialog({ agent, onClose, onSaved }: { agent: AgentDto; onClose: ()
             disabled={busy}
             onClick={async () => {
               const ok = await run(
-                () => api.patch(`/api/admin/agents/${agent.id}`, { name, labels: labels.split(',').map((x) => x.trim()).filter(Boolean), public_host: host, public_visible: visible }),
+                () => api.patch(`/api/admin/agents/${agent.id}`, { name, labels: labels.split(',').map((x) => x.trim()).filter(Boolean), public_host: host.trim(), ipv6_host: ipv6Host.trim(), public_visible: visible }),
                 '已保存',
               )
               if (ok) {
@@ -50,10 +51,15 @@ function EditDialog({ agent, onClose, onSaved }: { agent: AgentDto; onClose: ()
           </Field>
         </div>
         <div className="wide">
-          <Field label="公开地址" hint="Probe 用它连接这个 Agent：域名或 IP">
+          <Field label="IPv4 地址" hint="Probe 用它测 IPv4：IPv4 地址或域名（A 记录）">
             <input className="input" value={host} onChange={(e) => setHost(e.target.value)} />
           </Field>
         </div>
+        <div className="wide">
+          <Field label="IPv6 地址" hint="IPv6 地址或域名（AAAA 记录）；留空只采集 IPv4">
+            <input className="input" value={ipv6Host} onChange={(e) => setIpv6Host(e.target.value)} placeholder="例如 2001:db8::1 或 agent.example.com" />
+          </Field>
+        </div>
         <div className="wide">
           <Field label="标签" hint="逗号分隔">
             <input className="input" value={labels} onChange={(e) => setLabels(e.target.value)} />
@@ -167,9 +173,9 @@ export function AgentDetail() {
                 </thead>
                 <tbody>
                   {a.probes.map((p) => (
-                    <tr key={p.probe_id}>
+                    <tr key={`${p.probe_id}~${p.ip_version}`}>
                       <td>
-                        <div style={{ fontWeight: 600 }}>{probeName(p.probe_id)}</div>
+                        <div style={{ fontWeight: 600 }}>{probeName(p.probe_id)} <Chip>{p.ip_version === 'ipv6' ? 'IPv6' : 'IPv4'}</Chip></div>
                         <div className="mono faint">{p.probe_id}</div>
                       </td>
                       <td>{p.version ?? '—'}</td>
@@ -179,7 +185,7 @@ export function AgentDetail() {
                       </td>
                       <td className="r">
                         <span className="row" style={{ justifyContent: 'flex-end' }}>
-                          <Link className="btn small" to={`/tests?agent=${a.id}&probe=${p.probe_id}`}>
+                          <Link className="btn small" to={`/tests?agent=${a.id}&probe=${p.probe_id}&ip_version=${p.ip_version}`}>
                             <FlaskConical size={14} />
                             测试
                           </Link>
@@ -209,8 +215,12 @@ export function AgentDetail() {
               <dl className="kv">
                 <dt>ID</dt>
                 <dd className="mono">{a.id}</dd>
-                <dt>公开地址</dt>
+                <dt>IPv4 地址</dt>
                 <dd className="mono">{a.public_host || '—'}</dd>
+                <dt>IPv6 地址</dt>
+                <dd className="mono">{a.ipv6_host || '未配置'}</dd>
+                <dt>IPv6 监听</dt>
+                <dd>{a.ipv6_supported ? '已启用' : '未启用，请升级 Agent 并配置双栈监听'}</dd>
                 <dt>控制端口</dt>
                 <dd className="mono">{a.probe_tcp_port}/tcp</dd>
                 <dt>数据端口</dt>
diff --git a/web/admin/src/pages/Probes.tsx b/web/admin/src/pages/Probes.tsx
index 5629884..2c19aed 100644
--- a/web/admin/src/pages/Probes.tsx
+++ b/web/admin/src/pages/Probes.tsx
@@ -209,7 +209,7 @@ export function Probes() {
               ) : (
                 <>
                   <Chip tone={p.online ? 'ok' : ''}>{p.online ? '已连面板' : '未连面板'}</Chip>
-                  <Chip tone={p.connections.length > 0 ? 'ok' : ''}>{p.connections.length > 0 ? `连着 ${p.connections.length} 个 Agent` : '没有连接'}</Chip>
+                  <Chip tone={p.connections.length > 0 ? 'ok' : ''}>{p.connections.length > 0 ? `连着 ${new Set(p.connections.map((c) => c.agent_id)).size} 个 Agent` : '没有连接'}</Chip>
                 </>
               )}
               <span className="mono faint">{p.id}</span>
@@ -252,10 +252,11 @@ export function Probes() {
                 </thead>
                 <tbody>
                   {p.connections.map((c) => (
-                    <tr key={c.agent_id}>
+                    <tr key={`${c.agent_id}~${c.ip_version}`}>
                       <td>
                         <Link to={`/agents/${c.agent_id}`} style={{ fontWeight: 600 }}>
                           {c.agent_name}
+                          <Chip>{c.ip_version === 'ipv6' ? 'IPv6' : 'IPv4'}</Chip>
                         </Link>
                       </td>
                       <td>{c.version ?? '—'}</td>
diff --git a/web/admin/src/pages/Tests.tsx b/web/admin/src/pages/Tests.tsx
index 70c3da1..0dfb38f 100644
--- a/web/admin/src/pages/Tests.tsx
+++ b/web/admin/src/pages/Tests.tsx
@@ -1,5 +1,6 @@
 import { FlaskConical, Square } from 'lucide-react'
 import { useEffect, useState } from 'react'
+import { IpVersionPicker, ipVersionOf } from '@shared/ipVersions'
 import { useSearchParams } from 'react-router-dom'
 import { api } from '@shared/api/client'
 import type { AgentDto, Page, PlanDto, ProbeDto, TestDto } from '@shared/api/types'
@@ -84,6 +85,7 @@ function Result({ test }: { test: TestDto }) {
 
 export function Tests() {
   const [params, setParams] = useSearchParams()
+  const ipVersion = ipVersionOf(params.get('ip_version'))
   const agents = useQuery(() => api.get<Page<AgentDto>>('/api/admin/agents'), [], 10_000)
   const probes = useQuery(() => api.get<Page<ProbeDto>>('/api/admin/probes'), [])
   const plans = useQuery(() => api.get<Page<PlanDto>>('/api/public/catalog/plans'), [])
@@ -92,16 +94,18 @@ export function Tests() {
   const active = (agents.data?.items ?? []).filter((a) => a.status === 'active')
   const agentId = params.get('agent') ?? active[0]?.id ?? ''
   const agent = active.find((a) => a.id === agentId)
-  const connected = agent?.probes ?? []
+  const connected = (agent?.probes ?? []).filter((p) => ipVersionOf(p.ip_version) === ipVersion)
   const probeId = params.get('probe') ?? connected[0]?.probe_id ?? ''
   const [planId, setPlanId] = useState('')
   const [selected, setSelected] = useState<string>()
-  const line = agentId && probeId ? `${agentId}~${probeId}` : ''
+  const line = agentId && probeId ? `${agentId}~${probeId}${ipVersion === 'ipv6' ? '~ipv6' : ''}` : ''
 
   useEffect(() => {
     if (!planId && plans.data?.items[0]) setPlanId(plans.data.items[0].id)
   }, [plans.data, planId])
 
+  useEffect(() => { setSelected(undefined) }, [line])
+
   const tests = useQuery(() => (line ? api.get<Page<TestDto>>(`/api/admin/lines/${encodeURIComponent(line)}/tests`, { limit: 20 }) : Promise.resolve(undefined)), [line], 3000)
   const detail = useQuery(() => (selected ? api.get<TestDto>(`/api/public/tests/${selected}`) : Promise.resolve(undefined)), [selected, tests.data?.items[0]?.status], 3000)
   const probeName = (id: string) => probes.data?.items.find((p) => p.id === id)?.name ?? id
@@ -118,6 +122,7 @@ export function Tests() {
     <>
       <header>
         <h1>按需测试</h1>
+        <IpVersionPicker value={ipVersion} onChange={(v) => set({ ip_version: v })} />
         <span className="right">{agents.loading && !agents.data ? <Spinner /> : null}</span>
       </header>
       <ErrorNotice error={agents.error ?? plans.error ?? tests.error} />
@@ -190,7 +195,7 @@ export function Tests() {
             ) : (
               <table className="table hover">
                 <tbody>
-                  {tests.data?.items.map((t) => (
+                  {tests.data?.items.filter((t) => t.agent_id === agentId && t.probe_id === probeId && ipVersionOf(t.ip_version) === ipVersion).map((t) => (
                     <tr key={t.id} onClick={() => setSelected(t.id)} style={selected === t.id ? { background: 'var(--app-card-hover)' } : undefined}>
                       <td>
                         <Chip tone={STATUS[t.status]?.tone ?? ''}>{STATUS[t.status]?.label ?? t.status}</Chip>
@@ -221,7 +226,7 @@ export function Tests() {
           </div>
           <div className="card">
             <div className="card-title">结果</div>
-            {detail.data ? (
+            {detail.data && detail.data.id === selected && ipVersionOf(detail.data.ip_version) === ipVersion ? (
               <>
                 <p className="faint" style={{ marginBottom: 12 }}>
                   {detail.data.plan} · {STATUS[detail.data.status]?.label ?? detail.data.status}
diff --git a/web/display/src/App.tsx b/web/display/src/App.tsx
index cd5165a..a9279dd 100644
--- a/web/display/src/App.tsx
+++ b/web/display/src/App.tsx
@@ -1,20 +1,28 @@
 import { BuildFooter } from './BuildFooter'
-import { NavLink, Navigate, Route, Routes } from 'react-router-dom'
+import { NavLink, Navigate, Route, Routes, useLocation, useParams } from 'react-router-dom'
 import { SourceButton, ThemeToggle } from '@shared/ui'
 import { Compare } from './pages/Compare'
 import { Line } from './pages/Line'
 import { Overview } from './pages/Overview'
 
+function LineRoute() {
+  const { id } = useParams()
+  return <Line key={id} />
+}
+
 export function App() {
+  const location = useLocation()
+  const ipv6 = location.pathname.endsWith('~ipv6') || new URLSearchParams(location.search).get('ip_version') === 'ipv6'
+  const familyQuery = ipv6 ? '?ip_version=ipv6' : ''
   return (
     <>
       <header className="topbar">
         <div className="inner">
           <nav className="topnav">
-            <NavLink to="/" end className={({ isActive }) => (isActive ? 'active' : '')}>
+            <NavLink to={`/${familyQuery}`} end className={({ isActive }) => (isActive ? 'active' : '')}>
               总览
             </NavLink>
-            <NavLink to="/compare" className={({ isActive }) => (isActive ? 'active' : '')}>
+            <NavLink to={`/compare${familyQuery}`} className={({ isActive }) => (isActive ? 'active' : '')}>
               对比
             </NavLink>
             <a href="/admin/">管理</a>
@@ -25,7 +33,7 @@ export function App() {
       </header>
       <Routes>
         <Route path="/" element={<Overview />} />
-        <Route path="/line/:id" element={<Line />} />
+        <Route path="/line/:id" element={<LineRoute />} />
         <Route path="/compare" element={<Compare />} />
         <Route path="*" element={<Navigate to="/" replace />} />
       </Routes>
diff --git a/web/display/src/pages/Compare.tsx b/web/display/src/pages/Compare.tsx
index 362b3f4..f070d78 100644
--- a/web/display/src/pages/Compare.tsx
+++ b/web/display/src/pages/Compare.tsx
@@ -1,5 +1,6 @@
 import { Star } from 'lucide-react'
 import { useMemo } from 'react'
+import { IpVersionPicker, ipVersionOf } from '@shared/ipVersions'
 import { useSearchParams } from 'react-router-dom'
 import { api } from '@shared/api/client'
 import type { CompareDto, OverviewDto, OverviewLineDto } from '@shared/api/types'
@@ -54,15 +55,16 @@ interface Cell {
 
 export function Compare() {
   const [params, setParams] = useSearchParams()
+  const ipVersion = ipVersionOf(params.get('ip_version'))
   const range: PresetValue = isPreset(params.get('range')) ? (params.get('range') as PresetValue) : '1d'
   const metric = METRICS.find((m) => m.id === params.get('metric')) ?? METRICS[0]
-  const picked = useMemo(() => (params.get('lines') ?? '').split(',').filter(Boolean), [params])
+  const picked = useMemo(() => (params.get('lines') ?? '').split(',').filter((id) => id && id.endsWith('~ipv6') === (ipVersion === 'ipv6')), [params, ipVersion])
 
-  const overview = useQuery(() => api.get<OverviewDto>('/api/public/overview', { range, metrics: metric.id }), [range, metric.id], 15_000)
+  const overview = useQuery(() => api.get<OverviewDto>('/api/public/overview', { range, metrics: metric.id, ip_version: ipVersion }), [range, metric.id, ipVersion], 15_000)
 
   // 矩阵：行是 Agent，列是 Probe；每一列内部排名（同一个 Probe 看出去，哪个 Agent 的线路好）
   const matrix = useMemo(() => {
-    const lines = overview.data?.lines ?? []
+    const lines = (overview.data?.lines ?? []).filter((l) => ipVersionOf(l.ip_version) === ipVersion)
     const probes = [...new Map(lines.map((l) => [l.probe_id, l.probe_name])).entries()].sort((a, b) => a[1].localeCompare(b[1]))
     const agents = [...new Map(lines.map((l) => [l.agent_id, l.name])).entries()].sort((a, b) => a[1].localeCompare(b[1]))
     const byProbe = new Map<string, Cell[]>()
@@ -79,7 +81,7 @@ export function Compare() {
       byProbe.set(probeId, cells)
     }
     return { probes, agents, byProbe }
-  }, [overview.data, metric])
+  }, [overview.data, metric, ipVersion])
 
   // 默认选每个 Probe 里最好的那条线路（最多 6 条）
   const defaults = useMemo(() => {
@@ -123,6 +125,7 @@ export function Compare() {
         <h1>线路对比</h1>
         <p className="sub">同一个指标，在每个 Probe 看出去，哪个 Agent 的线路更好。</p>
         <div className="toolbar">
+          <IpVersionPicker value={ipVersion} onChange={(v) => update({ ip_version: v, lines: null })} />
           <Segmented options={PRESETS.map((p) => ({ value: p.value, label: p.label }))} value={range} onChange={(v) => update({ range: v })} />
           <select className="select" style={{ width: 'auto' }} value={metric.id} onChange={(e) => update({ metric: e.target.value })}>
             {METRICS.map((x) => (
diff --git a/web/display/src/pages/Line.tsx b/web/display/src/pages/Line.tsx
index 275ddae..136f28b 100644
--- a/web/display/src/pages/Line.tsx
+++ b/web/display/src/pages/Line.tsx
@@ -1,5 +1,6 @@
 import { ChevronLeft } from 'lucide-react'
 import { useMemo } from 'react'
+import { IP_VERSIONS, lineIdFor } from '@shared/ipVersions'
 import { Link, useParams, useSearchParams } from 'react-router-dom'
 import { api } from '@shared/api/client'
 import type { LineDto, TestDto } from '@shared/api/types'
@@ -245,7 +246,7 @@ export function Line() {
   return (
     <main className="page">
       <div className="crumbs">
-        <Link to="/" className="row">
+        <Link to={id.endsWith('~ipv6') ? '/?ip_version=ipv6' : '/'} className="row">
           <ChevronLeft size={16} />
           总览
         </Link>
@@ -256,6 +257,18 @@ export function Line() {
           {line.data?.name ?? '线路'}
           {line.data ? <span className="muted" style={{ fontWeight: 400 }}> → {line.data.probe_name}</span> : null}
         </h1>
+        <div className="row" style={{ marginTop: 12 }}>
+          {IP_VERSIONS.map((v) => {
+            const query = new URLSearchParams(params)
+            query.set('ip_version', v.value)
+            return (
+              <Link key={v.value} className={`btn small${(id.endsWith('~ipv6') ? 'ipv6' : 'ipv4') === v.value ? ' primary' : ''}`} to={`/line/${encodeURIComponent(lineIdFor(id, v.value))}?${query.toString()}`}>
+                {v.label}
+              </Link>
+            )
+          })}
+          {line.data && !line.data.ipv6_available && id.endsWith('~ipv6') ? <span className="muted">此 Agent 未配置 IPv6 地址</span> : null}
+        </div>
         {line.data ? (
           <div className="row wrap" style={{ marginTop: 12 }}>
             <Dot tone={line.data.online && line.data.probe_connected ? 'ok' : line.data.online ? 'warn' : 'bad'} />
diff --git a/web/display/src/pages/Overview.tsx b/web/display/src/pages/Overview.tsx
index bba68b9..f8f2a04 100644
--- a/web/display/src/pages/Overview.tsx
+++ b/web/display/src/pages/Overview.tsx
@@ -9,6 +9,7 @@ import { fmtBytes, fmtSpeed, fmtUptime, pct, useHosts, type HostItem } from '../
 import { Flag, IspIcon, useNodeInfos } from '@shared/nodes'
 import { OsIcon } from '@shared/osIcon'
 import { PageError } from '../lib'
+import { IpVersionPicker, ipVersionOf } from '@shared/ipVersions'
 import { LineStrips, OVERVIEW_RANGES, type OverviewRange } from '../LineStrips'
 
 const METRICS = ['rtt.p50', 'loss.total', 'loss.up', 'loss.down', 'tcp.rtt.p50', 'tcp.retrans'].join(',')
@@ -153,6 +154,7 @@ export function Overview() {
   const infos = useNodeInfos()
   // 近多久的汇总和走势：3 / 6 / 12 小时，记在链接里（?range=6h）
   const [params, setParams] = useSearchParams()
+  const ipVersion = ipVersionOf(params.get('ip_version'))
   const range: OverviewRange = OVERVIEW_RANGES.find((r) => r.value === params.get('range'))?.value ?? '3h'
   const setRange = (v: OverviewRange) =>
     setParams(
@@ -164,12 +166,13 @@ export function Overview() {
       },
       { replace: true },
     )
-  const { data, error, loading } = useQuery(() => api.get<OverviewDto>('/api/public/overview', { range, metrics: METRICS }), [range], 10_000)
+  const { data, error, loading } = useQuery(() => api.get<OverviewDto>('/api/public/overview', { range, metrics: METRICS, ip_version: ipVersion }), [range, ipVersion], 10_000)
 
   const probes = useMemo(() => [...new Set((data?.lines ?? []).map((l) => l.probe_name))].sort(), [data])
   const cards = useMemo(() => {
     const byAgent = new Map<string, AgentCard>()
     for (const l of data?.lines ?? []) {
+      if (ipVersionOf(l.ip_version) !== ipVersion) continue
       if (probe && l.probe_name !== probe) continue
       const card = byAgent.get(l.agent_id) ?? { id: l.agent_id, name: l.name, labels: l.labels, online: l.online, lines: [] }
       card.lines.push(l)
@@ -190,7 +193,7 @@ export function Overview() {
       if (y === null) return -1
       return x - y
     })
-  }, [data, probe, sort])
+  }, [data, probe, sort, ipVersion])
 
   const online = cards.filter((c) => c.online).length
 
@@ -203,6 +206,7 @@ export function Overview() {
           <span className={`live-dot ${live ? 'on' : ''}`} title={live ? '实时更新中' : '实时连接中断，正在重连'} />
         </p>
         <div className="toolbar">
+          <IpVersionPicker value={ipVersion} onChange={(v) => { const next = new URLSearchParams(params); next.set('ip_version', v); setProbe(''); setParams(next, { replace: true }) }} />
           {probes.length > 1 ? <Segmented options={[{ value: '', label: '全部 Probe' }, ...probes.map((p) => ({ value: p, label: p }))]} value={probe} onChange={setProbe} /> : null}
           <span className="right row">
             <Segmented<OverviewRange> options={OVERVIEW_RANGES.map((r) => ({ value: r.value, label: `近 ${r.label}` }))} value={range} onChange={setRange} />
@@ -225,7 +229,7 @@ export function Overview() {
       {data ? (
         cards.length === 0 ? (
           <div className="card" style={{ marginTop: 24 }}>
-            <Empty>还没有线路</Empty>
+            <Empty>{ipVersion === 'ipv6' ? '还没有 IPv6 线路，请在管理端配置 Agent 的 IPv6 地址' : '还没有线路'}</Empty>
           </div>
         ) : (
           <div className="cards">
diff --git a/web/shared/api/schema.ts b/web/shared/api/schema.ts
index 2616c78..b9293c8 100644
--- a/web/shared/api/schema.ts
+++ b/web/shared/api/schema.ts
@@ -1007,12 +1007,17 @@ export interface components {
             created_at: unknown;
             /** Format: date-time */
             last_seen_at: unknown;
+            /** @default  */
+            ipv6_host: string;
+            /** @default false */
+            ipv6_supported: boolean;
         };
         AgentPatchRequest: {
             name: null | string;
             labels: null | string[];
             public_host: null | string;
             public_visible: null | boolean;
+            ipv6_host?: null | string;
         };
         ApiTokenDto: {
             id: string;
@@ -1075,6 +1080,8 @@ export interface components {
             remote: null | string;
             /** Format: date-time */
             connected_since: unknown;
+            /** @default ipv4 */
+            ip_version: string;
         };
         CreateApiTokenRequest: {
             name: string;
@@ -1285,6 +1292,10 @@ export interface components {
             data_since: unknown;
             kinds: string[];
             last_test: null | components["schemas"]["TestSummaryDto"];
+            /** @default ipv4 */
+            ip_version: string;
+            /** @default false */
+            ipv6_available: boolean;
         };
         LinkDto: {
             probe_id: string;
@@ -1408,6 +1419,8 @@ export interface components {
             endpoint_changes: number | string;
             summary: components["schemas"]["SummaryDto"];
             last_test: null | components["schemas"]["TestSummaryDto"];
+            /** @default ipv4 */
+            ip_version: string;
         };
         PageDtoOfAgentDto: {
             items: components["schemas"]["AgentDto"][];
@@ -1527,6 +1540,8 @@ export interface components {
             remote: null | string;
             /** Format: date-time */
             connected_since: unknown;
+            /** @default ipv4 */
+            ip_version: string;
         };
         ProbeDto: {
             id: string;
@@ -1642,6 +1657,8 @@ export interface components {
             versions: {
                 [key: string]: string;
             };
+            /** @default ipv4 */
+            ip_version: string;
         };
         SetLinkRequest: {
             enabled: null | boolean;
@@ -1702,6 +1719,8 @@ export interface components {
             /** Format: date-time */
             finished_at: unknown;
             result: null | components["schemas"]["TestResultDto"];
+            /** @default ipv4 */
+            ip_version: string;
         };
         TestResultDto: {
             metrics: {
@@ -1762,6 +1781,7 @@ export interface operations {
                 metrics?: string;
                 sort?: string;
                 order?: string;
+                ip_version?: string;
             };
             header?: never;
             path?: never;
@@ -2191,7 +2211,9 @@ export interface operations {
     };
     live_stream: {
         parameters: {
-            query?: never;
+            query?: {
+                ip_version?: string;
+            };
             header?: never;
             path?: never;
             cookie?: never;
diff --git a/web/shared/ipVersions.tsx b/web/shared/ipVersions.tsx
new file mode 100644
index 0000000..4a0eb4f
--- /dev/null
+++ b/web/shared/ipVersions.tsx
@@ -0,0 +1,10 @@
+import { Segmented } from './ui'
+
+export type IpVersion = 'ipv4' | 'ipv6'
+export const ipVersionOf = (value: string | null | undefined): IpVersion => value === 'ipv6' ? 'ipv6' : 'ipv4'
+export const IP_VERSIONS: { value: IpVersion; label: string }[] = [{ value: 'ipv4', label: 'IPv4' }, { value: 'ipv6', label: 'IPv6' }]
+export const lineIdFor = (id: string, version: IpVersion): string => id.replace(/~ipv6$/, '') + (version === 'ipv6' ? '~ipv6' : '')
+
+export function IpVersionPicker({ value, onChange }: { value: IpVersion; onChange: (value: IpVersion) => void }) {
+  return <Segmented options={IP_VERSIONS} value={value} onChange={onChange} />
+}