diff --git a/client/client.go b/client/client.go
index cff45e7e..b84416e0 100644
--- a/client/client.go
+++ b/client/client.go
@@ -58,13 +58,9 @@ type QQClient struct {
 	oicq      *oicq.Codec
 
 	// internal state
-	waiters         sync.Map
-	servers         []*net.TCPAddr
-	currServerIndex int
-	retryTimes      int
-	version         *auth.AppVersion
-	deviceInfo      *auth.Device
-	alive           bool
+	waiters    sync.Map
+	version    *auth.AppVersion
+	deviceInfo *auth.Device
 
 	// session info
 	qwebSeq        atomic.Int64
@@ -139,8 +135,6 @@ func NewClientMd5(uin int64, passwordMd5 [16]byte) *QQClient {
 		msgSvcCache:     utils.NewCache(time.Second * 15),
 		transCache:      utils.NewCache(time.Second * 15),
 		onlinePushCache: utils.NewCache(time.Second * 15),
-		servers:         []*net.TCPAddr{},
-		alive:           true,
 		highwaySession:  new(highway.Session),
 
 		pending:    make(map[int32]*network.Call),
@@ -166,27 +160,29 @@ func NewClientMd5(uin int64, passwordMd5 [16]byte) *QQClient {
 	cli.UseDevice(SystemDeviceInfo)
 	sso, err := getSSOAddress()
 	if err == nil && len(sso) > 0 {
-		cli.servers = append(sso, cli.servers...)
+		for _, addr := range sso {
+			cli.transport.AddServerAddr(addr)
+		}
 	}
 	adds, err := net.LookupIP("msfwifi.3g.qq.com") // host servers
 	if err == nil && len(adds) > 0 {
-		var hostAddrs []*net.TCPAddr
 		for _, addr := range adds {
-			hostAddrs = append(hostAddrs, &net.TCPAddr{
+			cli.transport.AddServerAddr(&net.TCPAddr{
 				IP:   addr,
 				Port: 8080,
 			})
 		}
-		cli.servers = append(hostAddrs, cli.servers...)
 	}
-	if len(cli.servers) == 0 {
-		cli.servers = []*net.TCPAddr{ // default servers
+	if cli.transport.ServerCount() == 0 {
+		for _, addr := range []*net.TCPAddr{ // default servers
 			{IP: net.IP{42, 81, 172, 22}, Port: 80},
 			{IP: net.IP{42, 81, 172, 81}, Port: 80},
 			{IP: net.IP{42, 81, 172, 147}, Port: 443},
 			{IP: net.IP{114, 221, 144, 215}, Port: 80},
 			{IP: net.IP{114, 221, 148, 59}, Port: 14000},
 			{IP: net.IP{125, 94, 60, 146}, Port: 80},
+		} {
+			cli.transport.AddServerAddr(addr)
 		}
 	}
 	/*pings := make([]int64, len(cli.servers))
@@ -227,7 +223,6 @@ func (c *QQClient) Release() {
 	if c.Online.Load() {
 		c.Disconnect()
 	}
-	c.alive = false
 }
 
 // Login send login request
@@ -831,7 +826,9 @@ func (g *GroupInfo) removeMember(uin int64) {
 }
 
 func (c *QQClient) SetCustomServer(servers []*net.TCPAddr) {
-	c.servers = append(servers, c.servers...)
+	for _, server := range servers {
+		c.transport.AddServerAddr(server)
+	}
 }
 
 func (c *QQClient) registerClient() error {
diff --git a/client/internal/network/transport.go b/client/internal/network/transport.go
index 2b700a20..8fa187bd 100644
--- a/client/internal/network/transport.go
+++ b/client/internal/network/transport.go
@@ -3,10 +3,12 @@ package network
 import (
 	goBinary "encoding/binary"
 	"fmt"
-	"github.com/pkg/errors"
 	"io"
 	"net"
 	"strconv"
+	"sync"
+
+	"github.com/pkg/errors"
 
 	"github.com/Mrs4s/MiraiGo/binary"
 	"github.com/Mrs4s/MiraiGo/client/internal/auth"
@@ -20,7 +22,28 @@ type Transport struct {
 	Device  *auth.Device
 
 	// connection
-	conn TCPListener
+	connMu        sync.Mutex
+	servers       []*net.TCPAddr
+	curServerAddr *net.TCPAddr
+	conn          TCPListener
+}
+
+func (t *Transport) AddServerAddr(addr *net.TCPAddr) {
+	t.connMu.Lock()
+	defer t.connMu.Unlock()
+	t.servers = append(t.servers, addr)
+}
+
+func (t *Transport) GetServerAddr() *net.TCPAddr {
+	t.connMu.Lock()
+	defer t.connMu.Unlock()
+	return t.curServerAddr
+}
+
+func (t *Transport) ServerCount() int {
+	t.connMu.Lock()
+	defer t.connMu.Unlock()
+	return len(t.servers)
 }
 
 func (t *Transport) PlannedDisconnect(fun func(*TCPListener)) {
@@ -31,8 +54,12 @@ func (t *Transport) UnexpectedDisconnect(fun func(*TCPListener, error)) {
 	t.conn.UnexpectedDisconnect = fun
 }
 
-func (t *Transport) ConnectFastest(servers []*net.TCPAddr) (chosen *net.TCPAddr, err error) {
-	return t.conn.ConnectFastest(servers)
+func (t *Transport) ConnectFastest() (chosen *net.TCPAddr, err error) {
+	t.connMu.Lock()
+	defer t.connMu.Unlock()
+	chosen, err = t.conn.ConnectFastest(t.servers)
+	t.curServerAddr = chosen
+	return
 }
 
 func (t *Transport) Close() {
diff --git a/client/network.go b/client/network.go
index b784995c..447de6e0 100644
--- a/client/network.go
+++ b/client/network.go
@@ -44,7 +44,7 @@ func (c *QQClient) ConnectionQualityTest() *ConnectionQualityInfo {
 		defer wg.Done()
 		var err error
 
-		if r.ChatServerLatency, err = qualityTest(c.servers[c.currServerIndex].String()); err != nil {
+		if r.ChatServerLatency, err = qualityTest(c.transport.GetServerAddr().String()); err != nil {
 			c.Error("test chat server latency error: %v", err)
 			r.ChatServerLatency = 9999
 		}
@@ -67,7 +67,7 @@ func (c *QQClient) ConnectionQualityTest() *ConnectionQualityInfo {
 	}()
 	go func() {
 		defer wg.Done()
-		res := utils.RunTCPPingLoop(c.servers[c.currServerIndex].String(), 10)
+		res := utils.RunTCPPingLoop(c.transport.GetServerAddr().String(), 10)
 		r.ChatServerPacketLoss = res.PacketsLoss
 		if c.highwaySession.AddrLength() > 0 {
 			res = utils.RunTCPPingLoop(c.highwaySession.SsoAddr[0].String(), 10)
@@ -87,14 +87,13 @@ func (c *QQClient) ConnectionQualityTest() *ConnectionQualityInfo {
 
 func (c *QQClient) connectFastest() error {
 	c.Disconnect()
-	addr, err := c.transport.ConnectFastest(c.servers)
+	addr, err := c.transport.ConnectFastest()
 	if err != nil {
 		c.Disconnect()
 		return err
 	}
 	c.Debug("connected to server: %v [fastest]", addr.String())
 	c.transport.NetLoop(c.pktProc, c.transport.ReadRequest)
-	c.retryTimes = 0
 	c.ConnectTime = time.Now()
 	return nil
 }