diff --git a/cmd/cli/cli.go b/cmd/cli/cli.go
index 6b7ac8f..4934c5a 100644
--- a/cmd/cli/cli.go
+++ b/cmd/cli/cli.go
@@ -1723,20 +1723,22 @@ func upgradeUrl(baseUrl string) string {
 }
 
 // runningIface returns the value of the iface variable used by ctrld process which is running.
-func runningIface(s service.Service) string {
+func runningIface(s service.Service) *ifaceResponse {
 	if sockDir, err := socketDir(); err == nil {
 		if cc := newSocketControlClient(context.TODO(), s, sockDir); cc != nil {
 			resp, err := cc.post(ifacePath, nil)
 			if err != nil {
-				return ""
+				return nil
 			}
 			defer resp.Body.Close()
-			if buf, _ := io.ReadAll(resp.Body); len(buf) > 0 {
-				return string(buf)
+			res := &ifaceResponse{}
+			if err := json.NewDecoder(resp.Body).Decode(res); err != nil {
+				return nil
 			}
+			return res
 		}
 	}
-	return ""
+	return nil
 }
 
 // resetDnsNoLog performs resetting DNS with logging disable.
@@ -1754,7 +1756,7 @@ func resetDnsNoLog(p *prog) {
 }
 
 // resetDnsTask returns a task which perform reset DNS operation.
-func resetDnsTask(p *prog, s service.Service, isCtrldInstalled bool, currentRunningIface string) task {
+func resetDnsTask(p *prog, s service.Service, isCtrldInstalled bool, ir *ifaceResponse) task {
 	return task{func() error {
 		if iface == "" {
 			return nil
@@ -1764,8 +1766,10 @@ func resetDnsTask(p *prog, s service.Service, isCtrldInstalled bool, currentRunn
 		// process to reset what setDNS has done properly.
 		oldIface := iface
 		iface = "auto"
-		if currentRunningIface != "" {
-			iface = currentRunningIface
+		p.requiredMultiNICsConfig = requiredMultiNICsConfig()
+		if ir != nil {
+			iface = ir.Name
+			p.requiredMultiNICsConfig = ir.All
 		}
 		p.runningIface = iface
 		if isCtrldInstalled {
diff --git a/cmd/cli/commands.go b/cmd/cli/commands.go
index ebf3dec..0982647 100644
--- a/cmd/cli/commands.go
+++ b/cmd/cli/commands.go
@@ -197,7 +197,7 @@ NOTE: running "ctrld start" without any arguments will start already installed c
 			isCtrldInstalled := !errors.Is(err, service.ErrNotInstalled)
 
 			// Get current running iface, if any.
-			var currentIface string
+			var currentIface *ifaceResponse
 
 			// If pin code was set, do not allow running start command.
 			if isCtrldRunning {
@@ -522,9 +522,10 @@ func initStopCmd() *cobra.Command {
 				mainLog.Load().Error().Msg(err.Error())
 				return
 			}
-			p.runningIface = iface
-			if ri := runningIface(s); ri != "" {
-				p.runningIface = ri
+			p.preRun()
+			if ir := runningIface(s); ir != nil {
+				p.runningIface = ir.Name
+				p.requiredMultiNICsConfig = ir.All
 			}
 
 			initLogging()
@@ -610,7 +611,9 @@ func initRestartCmd() *cobra.Command {
 				doValidateCdRemoteConfig(cdUID)
 			}
 
-			iface = runningIface(s)
+			if ir := runningIface(s); ir != nil {
+				iface = ir.Name
+			}
 			tasks := []task{
 				{s.Stop, false},
 				{s.Start, true},
@@ -777,9 +780,10 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 			if iface == "" {
 				iface = "auto"
 			}
-			p.runningIface = iface
-			if ri := runningIface(s); ri != "" {
-				p.runningIface = ri
+			p.preRun()
+			if ir := runningIface(s); ir != nil {
+				p.runningIface = ir.Name
+				p.requiredMultiNICsConfig = ir.All
 			}
 			if err := checkDeactivationPin(s, nil); isCheckDeactivationPinErr(err) {
 				os.Exit(deactivationPinInvalidExitCode)
diff --git a/cmd/cli/control_server.go b/cmd/cli/control_server.go
index 52406b1..d1daea3 100644
--- a/cmd/cli/control_server.go
+++ b/cmd/cli/control_server.go
@@ -31,6 +31,11 @@ const (
 	sendLogsPath     = "/logs/send"
 )
 
+type ifaceResponse struct {
+	Name string `json:"name"`
+	All  bool   `json:"all"`
+}
+
 type controlServer struct {
 	server *http.Server
 	mux    *http.ServeMux
@@ -205,15 +210,20 @@ func (p *prog) registerControlServerHandler() {
 		w.WriteHeader(http.StatusBadRequest)
 	}))
 	p.cs.register(ifacePath, http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
+		res := &ifaceResponse{Name: iface}
 		// p.setDNS is only called when running as a service
 		if !service.Interactive() {
 			<-p.csSetDnsDone
 			if p.csSetDnsOk {
-				w.Write([]byte(iface))
-				return
+				res.Name = p.runningIface
+				res.All = p.requiredMultiNICsConfig
 			}
 		}
-		w.WriteHeader(http.StatusBadRequest)
+		if err := json.NewEncoder(w).Encode(res); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			http.Error(w, fmt.Sprintf("could not marshal iface data: %v", err), http.StatusInternalServerError)
+			return
+		}
 	}))
 	p.cs.register(viewLogsPath, http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
 		lr, err := p.logReader()