diff --git a/main.cpp b/main.cpp
index cd1e9eb..4e979d6 100644
--- a/main.cpp
+++ b/main.cpp
@@ -39,6 +39,8 @@ static void print_help()
 
 
 	printf("advanced options:\n");
+	printf("    -b,--bind             ip:port         force all output packets to go through this address. Set port to 0 to use a random one.\n");
+	printf("    --interface           <string>        force all output packets to go through this interface.\n");
 	printf("    --mode                <number>        fec-mode,available values: 0,1; mode 0(default) costs less bandwidth,no mtu problem.\n");
 	printf("                                          mode 1 usually introduces less latency, but you have to care about mtu.\n");
 	printf("    --mtu                 <number>        mtu for fec. for mode 0, the program will split packet to segment smaller than mtu.\n");
diff --git a/tun_dev_client.cpp b/tun_dev_client.cpp
index 4f2ed3c..dc8f2c9 100644
--- a/tun_dev_client.cpp
+++ b/tun_dev_client.cpp
@@ -213,7 +213,7 @@ int tun_dev_client_event_loop()
 	tun_fd=get_tun_fd(tun_dev);
 	assert(tun_fd>0);
 
-	assert(new_connected_socket2(remote_fd,remote_addr)==0);
+	assert(new_connected_socket2(remote_fd,remote_addr,has_b,bind_addr,interface_string)==0);
 	remote_fd64=fd_manager.create(remote_fd);
 
 	assert(set_tun(tun_dev,htonl((ntohl(sub_net_uint32)&0xFFFFFF00)|2),htonl((ntohl(sub_net_uint32)&0xFFFFFF00 )|1),tun_mtu)==0);