diff --git a/tun2socks/SocksUdpGwClient.c b/tun2socks/SocksUdpGwClient.c
index 842c8983..db0bf265 100644
--- a/tun2socks/SocksUdpGwClient.c
+++ b/tun2socks/SocksUdpGwClient.c
@@ -617,16 +617,20 @@ void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr
         // create new connection
         con = connection_init(o, conaddr, data, data_len, is_dns);
     } else {
-        // move connection to front of the list
-        LinkedList1_Remove(&o->connections_list, &con->connections_list_node);
-        LinkedList1_Append(&o->connections_list, &con->connections_list_node);
-
         // reset the connection
         reset_connection(o, con, conaddr, is_dns);
 
         // send packet to existing connection
-        // drop the packet if out of buffer
-        connection_send(con, data, data_len);
+        int res = connection_send(con, data, data_len);
+
+        if (res == 1) {
+            // drop the packet if out of buffer
+            BLog(BLOG_ERROR, "Drop the packet as the buffer is full");
+        } else {
+            // move connection to front of the list
+            LinkedList1_Remove(&o->connections_list, &con->connections_list_node);
+            LinkedList1_Append(&o->connections_list, &con->connections_list_node);
+        }
     }
 #else
     // submit to udpgw client