diff --git a/probe.go b/probe.go
index 90ecf16..2604cdb 100644
--- a/probe.go
+++ b/probe.go
@@ -52,7 +52,7 @@ func main() {
 	var err error
 	if s5 != "" {
 		fmt.Printf("通过代理探测: %s\n", s5)
-		conn, err = DialSocks5UDP(s5)
+		conn, err = DialSocks5UDP(s5, network)
 		if err != nil {
 			fmt.Printf("连接代理失败: %v\n", err)
 			return
diff --git a/probe_nat.go b/probe_nat.go
index b35b2cf..cdd84b4 100644
--- a/probe_nat.go
+++ b/probe_nat.go
@@ -149,6 +149,14 @@ func DetectNAT(conn net.PacketConn, primarySTUN, secondarySTUN, network string,
 		return res
 	}
 	res.MappedIP = mappedAddr1.String()
+	if localAddr, ok := conn.LocalAddr().(*net.UDPAddr); ok {
+		if localAddr.IP.Equal(mappedAddr1.IP) && localAddr.Port == mappedAddr1.Port {
+			res.Type = NATOpen
+			res.Mapping = MappingEndpointIndependent
+			res.Filtering = FilteringEndpointIndependent
+			return res
+		}
+	}
 	var targetSTUN2 string
 	if secondarySTUN != "" {
 		targetSTUN2 = secondarySTUN
@@ -160,7 +168,10 @@ func DetectNAT(conn net.PacketConn, primarySTUN, secondarySTUN, network string,
 			host, port, _ := net.SplitHostPort(primarySTUN)
 			ips, err := net.LookupIP(host)
 			if err == nil && len(ips) > 1 {
-				primaryIP, _ := net.ResolveIPAddr("ip", host)
+				primaryIP, err := net.ResolveIPAddr("ip", host)
+				if err != nil {
+					return res
+				}
 				wantIPv4 := network == "udp4"
 				wantIPv6 := network == "udp6"
 				if network == "udp" {
diff --git a/probe_socks5.go b/probe_socks5.go
index e5f9afb..feef126 100644
--- a/probe_socks5.go
+++ b/probe_socks5.go
@@ -180,9 +180,9 @@ func (c *socks5PacketConn) SetWriteDeadline(t time.Time) error {
 }
 
 // DialSocks5UDP 建立SOCKS5 UDP关联
-// 入参: proxyAddr 代理服务器地址
+// 入参: proxyAddr 代理服务器地址, network 网络协议(udp/udp4/udp6)
 // 返回: conn 数据包连接, err 连接错误
-func DialSocks5UDP(proxyAddr string) (net.PacketConn, error) {
+func DialSocks5UDP(proxyAddr, network string) (net.PacketConn, error) {
 	var host string
 	if strings.Contains(proxyAddr, "://") {
 		u, err := url.Parse(proxyAddr)
@@ -193,7 +193,14 @@ func DialSocks5UDP(proxyAddr string) (net.PacketConn, error) {
 	} else {
 		host = proxyAddr
 	}
-	conn, err := net.DialTimeout("tcp", host, 5*time.Second)
+	tcpNetwork := "tcp"
+	switch network {
+	case "udp4":
+		tcpNetwork = "tcp4"
+	case "udp6":
+		tcpNetwork = "tcp6"
+	}
+	conn, err := net.DialTimeout(tcpNetwork, host, 5*time.Second)
 	if err != nil {
 		return nil, err
 	}
@@ -272,7 +279,7 @@ func DialSocks5UDP(proxyAddr string) (net.PacketConn, error) {
 		}
 	}
 	relayAddr := &net.UDPAddr{IP: relayIP, Port: relayPort}
-	lConn, err := net.ListenUDP("udp", nil)
+	lConn, err := net.ListenUDP(network, nil)
 	if err != nil {
 		conn.Close()
 		return nil, err