@@ -348,10 +348,8 @@ func (sb *Sandbox) populateNetworkResources(ctx context.Context, ep *Endpoint) (

 	// Populate DNS records.

 	n := ep.getNetwork()

-	if !n.getController().isAgent() {

-		if !n.getController().isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {

-			n.updateSvcRecord(context.WithoutCancel(ctx), ep, true)

-		}

+	if !n.getController().isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {

+		n.updateSvcRecord(context.WithoutCancel(ctx), ep, true)

 	}

 	if err := ep.addDriverInfoToCluster(); err != nil {

@@ -1092,7 +1092,7 @@ func TestDisableIPv6OnInterface(t *testing.T) {

 			// There should not be an IPv6 DNS or /etc/hosts entry.

 			runRes := container.RunAttach(ctx, t, c,

 				container.WithNetworkMode(tc.netName),

-				container.WithCmd("ping", "-6", ctrName),

+				container.WithCmd("ping", "-6", "-c1", ctrName),

 			)

 			assert.Check(t, is.Equal(runRes.ExitCode, 1))

 			assert.Check(t, is.Contains(runRes.Stderr.String(), "bad address"))

@@ -2032,3 +2032,29 @@ func TestLegacyLinksEnvVars(t *testing.T) {

 		})

 	}

 }

+

+// TestDNSNamesForNonSwarmScopedNetworks checks that container names can be resolved for non-swarm-scoped networks once

+// a node has joined a Swarm cluster.

+//

+// Regression test for https://github.com/moby/moby/issues/51491.

+func TestDNSNamesForNonSwarmScopedNetworks(t *testing.T) {

+	ctx := setupTest(t)

+

+	d := daemon.New(t)

+	d.StartAndSwarmInit(ctx, t)

+	defer d.Stop(t)

+

+	c := d.NewClientT(t)

+	defer c.Close()

+

+	const bridgeName = "dnsnames-with-swarm"

+	network.CreateNoError(ctx, t, c, bridgeName)

+	defer network.RemoveNoError(ctx, t, c, bridgeName)

+

+	res := container.RunAttach(ctx, t, c,

+		container.WithName("test"),

+		container.WithCmd("nslookup", "-type=a", "test."),

+		container.WithNetworkMode(bridgeName),

+		container.WithAutoRemove)

+	assert.Equal(t, res.ExitCode, 0, "exit code: %d, expected 0; stdout:\n%s", res.ExitCode, res.Stdout)

+}