diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go
index 3ffeaba87..8346b59a7 100644
--- a/control/controlclient/direct.go
+++ b/control/controlclient/direct.go
@@ -620,6 +620,7 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			Hostinfo:     resp.Node.Hostinfo,
 			PacketFilter: c.parsePacketFilter(resp.PacketFilter),
 			DERPMap:      lastDERPMap,
+			Debug:        resp.Debug,
 		}
 		for _, profile := range resp.UserProfiles {
 			nm.UserProfiles[profile.ID] = profile
diff --git a/control/controlclient/netmap.go b/control/controlclient/netmap.go
index 71c00f90c..0556a25e4 100644
--- a/control/controlclient/netmap.go
+++ b/control/controlclient/netmap.go
@@ -39,6 +39,9 @@ type NetworkMap struct {
 	// between updates and should not be modified.
 	DERPMap *tailcfg.DERPMap
 
+	// Debug knobs from control server for debug or feature gating.
+	Debug *tailcfg.Debug
+
 	// ACLs
 
 	User   tailcfg.UserID
@@ -70,9 +73,17 @@ func (nm NetworkMap) String() string {
 
 func (nm *NetworkMap) Concise() string {
 	buf := new(strings.Builder)
-	fmt.Fprintf(buf, "netmap: self: %v auth=%v :%v %v\n",
-		nm.NodeKey.ShortString(), nm.MachineStatus,
-		nm.LocalPort, nm.Addresses)
+	fmt.Fprintf(buf, "netmap: self: %v auth=%v",
+		nm.NodeKey.ShortString(), nm.MachineStatus)
+	if nm.LocalPort != 0 {
+		fmt.Fprintf(buf, " port=%v", nm.LocalPort)
+	}
+	if nm.Debug != nil {
+		j, _ := json.Marshal(nm.Debug)
+		fmt.Fprintf(buf, " debug=%s", j)
+	}
+	fmt.Fprintf(buf, " %v", nm.Addresses)
+	buf.WriteByte('\n')
 	for _, p := range nm.Peers {
 		aip := make([]string, len(p.AllowedIPs))
 		for i, a := range p.AllowedIPs {
diff --git a/control/controlclient/netmap_test.go b/control/controlclient/netmap_test.go
index 93f511b75..d9c23b93c 100644
--- a/control/controlclient/netmap_test.go
+++ b/control/controlclient/netmap_test.go
@@ -11,26 +11,62 @@ import (
 )
 
 func TestNetworkMapConcise(t *testing.T) {
-	nm := &NetworkMap{
-		Peers: []*tailcfg.Node{
-			{
-				Name:      "foo",
-				Endpoints: []string{"192.168.0.100:12", "192.168.0.100:12354"},
+	nodekey := func(b byte) (ret tailcfg.NodeKey) {
+		for i := range ret {
+			ret[i] = b
+		}
+		return
+	}
+	for _, tt := range []struct {
+		name string
+		nm   *NetworkMap
+		want string
+	}{
+		{
+			name: "basic",
+			nm: &NetworkMap{
+				NodeKey: nodekey(1),
+				Peers: []*tailcfg.Node{
+					{
+						Key:       nodekey(2),
+						DERP:      "127.3.3.40:2",
+						Endpoints: []string{"192.168.0.100:12", "192.168.0.100:12354"},
+					},
+					{
+						Key:       nodekey(3),
+						DERP:      "127.3.3.40:4",
+						Endpoints: []string{"10.2.0.100:12", "10.1.0.100:12345"},
+					},
+				},
 			},
-			{
-				Name:      "bar",
-				Endpoints: []string{"10.2.0.100:12", "10.1.0.100:12345"},
+			want: "netmap: self: [AQEBA] auth=machine-unknown []\n [AgICA] D2                 :    192.168.0.100:12     192.168.0.100:12354\n [AwMDA] D4                 :       10.2.0.100:12        10.1.0.100:12345\n",
+		},
+		{
+			name: "debug_non_nil",
+			nm: &NetworkMap{
+				NodeKey: nodekey(1),
+				Debug:   &tailcfg.Debug{},
 			},
+			want: "netmap: self: [AQEBA] auth=machine-unknown debug={} []\n",
 		},
-	}
-	var got string
-	n := int(testing.AllocsPerRun(1000, func() {
-		got = nm.Concise()
-	}))
-	t.Logf("Allocs = %d", n)
-	want := "netmap: self: [AAAAA] auth=machine-unknown :0 []\n" +
-		" [AAAAA]                    :    192.168.0.100:12     192.168.0.100:12354\n [AAAAA]                    :       10.2.0.100:12        10.1.0.100:12345\n"
-	if got != want {
-		t.Errorf("Wrong output\n Got: %q\nWant: %q\n## Got (unescaped):\n%s\n## Want (unescaped):\n%s\n", got, want, got, want)
+		{
+			name: "debug_values",
+			nm: &NetworkMap{
+				NodeKey: nodekey(1),
+				Debug:   &tailcfg.Debug{LogHeapPprof: true},
+			},
+			want: "netmap: self: [AQEBA] auth=machine-unknown debug={\"LogHeapPprof\":true} []\n",
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			var got string
+			n := int(testing.AllocsPerRun(1000, func() {
+				got = tt.nm.Concise()
+			}))
+			t.Logf("Allocs = %d", n)
+			if got != tt.want {
+				t.Errorf("Wrong output\n Got: %q\nWant: %q\n## Got (unescaped):\n%s\n## Want (unescaped):\n%s\n", got, tt.want, got, tt.want)
+			}
+		})
 	}
 }