diff --git a/.docker/build b/.docker/build
index 74dab774..512d3298 100755
--- a/.docker/build
+++ b/.docker/build
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# sudo docker run -p 80:8080 -p 59000-59100:59000-59100/udp --cap-add SYS_ADMIN nurdism/neko:chromium 
+# sudo docker run -p 80:8080 -p 59000-59100:59000-59100/udp --cap-add SYS_ADMIN --shm-size=1gb nurdism/neko:chromium 
 # sudo docker run -p 80:8080 -p 59000-59100:59000-59100/udp --shm-size=1gb nurdism/neko:firefox
 # sudo docker run --network host --shm-size=1gb -it nurdism/neko:base /bin/bash
 
diff --git a/client/src/neko/base.ts b/client/src/neko/base.ts
index 7998098d..534694be 100644
--- a/client/src/neko/base.ts
+++ b/client/src/neko/base.ts
@@ -151,9 +151,7 @@ export abstract class BaseClient extends EventEmitter<BaseEvents> {
       return
     }
 
-    this._peer = new RTCPeerConnection({
-      iceServers: [{ urls: 'stun:stun.l.google.com:19302' }],
-    })
+    this._peer = new RTCPeerConnection()
 
     this._peer.onicecandidate = event => {
       if (event.candidate === null && this._peer!.localDescription) {
@@ -167,9 +165,18 @@ export abstract class BaseClient extends EventEmitter<BaseEvents> {
       }
     }
 
+    this._peer.onsignalingstatechange = event => {
+      this.emit('debug', `peer signal state chagned: ${this._peer!.signalingState}`)
+    }
+
+    this._peer.onconnectionstatechange = event => {
+      this.emit('debug', `peer connection state chagned: ${this._peer!.connectionState}`)
+    }
+
     this._peer.oniceconnectionstatechange = event => {
       this._state = this._peer!.iceConnectionState
-      this.emit('debug', `peer connection state chagned: ${this._state}`)
+
+      this.emit('debug', `peer ice connection state chagned: ${this._peer!.iceConnectionState}`)
 
       switch (this._state) {
         case 'checking':
diff --git a/client/vue.config.js b/client/vue.config.js
index 3a0748ba..2ade23d0 100644
--- a/client/vue.config.js
+++ b/client/vue.config.js
@@ -1,6 +1,7 @@
 const path = require('path')
 
 module.exports = {
+  productionSourceMap: false,
   css: {
     loaderOptions: {
       sass: {
diff --git a/server/internal/types/config/webrtc.go b/server/internal/types/config/webrtc.go
index 094cdc96..875fd5a7 100644
--- a/server/internal/types/config/webrtc.go
+++ b/server/internal/types/config/webrtc.go
@@ -7,17 +7,19 @@ import (
 	"github.com/pion/webrtc/v2"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
+	"n.eko.moe/neko/internal/utils"
 )
 
 type WebRTC struct {
-	Device         string
-	AudioCodec     string
-	AudioParams    string
-	Display        string
-	VideoCodec     string
-	VideoParams    string
-	EphemeralStart uint16
-	EphemeralEnd   uint16
+	Device       string
+	AudioCodec   string
+	AudioParams  string
+	Display      string
+	VideoCodec   string
+	VideoParams  string
+	EphemeralMin uint16
+	EphemeralMax uint16
+	NAT1To1IPs   []string
 }
 
 func (WebRTC) Init(cmd *cobra.Command) error {
@@ -83,6 +85,11 @@ func (WebRTC) Init(cmd *cobra.Command) error {
 		return err
 	}
 
+	cmd.PersistentFlags().StringSlice("ip", []string{}, "sets a list of external IP addresses of 1:1 (D)NAT and a candidate type for which the external IP address is used")
+	if err := viper.BindPFlag("ip", cmd.PersistentFlags().Lookup("ip")); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -113,19 +120,34 @@ func (s *WebRTC) Set() {
 	s.Display = viper.GetString("display")
 	s.VideoCodec = videoCodec
 	s.VideoParams = viper.GetString("vparams")
-	s.EphemeralStart = 59000
-	s.EphemeralEnd = 59100
+	s.NAT1To1IPs = viper.GetStringSlice("ip")
 
+	ip, err := utils.GetIP()
+	if err == nil {
+		s.NAT1To1IPs = append(s.NAT1To1IPs, ip)
+	}
+
+	min := uint16(59000)
+	max := uint16(59100)
 	epr := viper.GetString("epr")
 	ports := strings.SplitN(epr, "-", -1)
 	if len(ports[0]) > 1 {
 		start, err := strconv.ParseUint(ports[0], 16, 16)
 		if err == nil {
-			s.EphemeralStart = uint16(start)
+			min = uint16(start)
 		}
+
 		end, err := strconv.ParseUint(ports[1], 16, 16)
 		if err == nil {
-			s.EphemeralEnd = uint16(end)
+			max = uint16(end)
 		}
 	}
+
+	if min > max {
+		s.EphemeralMin = max
+		s.EphemeralMax = min
+	} else {
+		s.EphemeralMin = min
+		s.EphemeralMax = max
+	}
 }
diff --git a/server/internal/utils/ip.go b/server/internal/utils/ip.go
new file mode 100644
index 00000000..69798a86
--- /dev/null
+++ b/server/internal/utils/ip.go
@@ -0,0 +1,24 @@
+package utils
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+)
+
+// dig @resolver1.opendns.com ANY myip.opendns.com +short -4
+
+func GetIP() (string, error) {
+	rsp, err := http.Get("http://checkip.amazonaws.com")
+	if err != nil {
+		return "", err
+	}
+	defer rsp.Body.Close()
+
+	buf, err := ioutil.ReadAll(rsp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	return string(bytes.TrimSpace(buf)), nil
+}
diff --git a/server/internal/webrtc/webrtc.go b/server/internal/webrtc/webrtc.go
index 90f79f5d..a25f308b 100644
--- a/server/internal/webrtc/webrtc.go
+++ b/server/internal/webrtc/webrtc.go
@@ -22,8 +22,10 @@ func New(sessions types.SessionManager, config *config.WebRTC) *WebRTCManager {
 		},
 	}
 
+	settings.SetLite(true)
 	settings.SetNetworkTypes([]webrtc.NetworkType{webrtc.NetworkTypeUDP4})
-	settings.SetEphemeralUDPPortRange(config.EphemeralStart, config.EphemeralEnd)
+	settings.SetEphemeralUDPPortRange(config.EphemeralMin, config.EphemeralMax)
+	settings.SetNAT1To1IPs(config.NAT1To1IPs, webrtc.ICECandidateTypeHost)
 
 	return &WebRTCManager{
 		logger:   logger,
@@ -33,11 +35,6 @@ func New(sessions types.SessionManager, config *config.WebRTC) *WebRTCManager {
 		sessions: sessions,
 		config:   config,
 		configuration: &webrtc.Configuration{
-			ICEServers: []webrtc.ICEServer{
-				{
-					URLs: []string{"stun:stun.l.google.com:19302"},
-				},
-			},
 			SDPSemantics: webrtc.SDPSemanticsUnifiedPlanWithFallback,
 		},
 	}