diff --git a/common.h b/common.h
index a4a45ac..7914ad0 100644
--- a/common.h
+++ b/common.h
@@ -85,7 +85,7 @@ struct ip_port_t
 
 typedef u64_t fd64_t;
 
-const int max_data_len=1600;
+const int max_data_len=1800;
 const int buf_len=max_data_len+400;
 
 u64_t get_current_time();
diff --git a/main.cpp b/main.cpp
index 22ba2dd..10d7fd1 100755
--- a/main.cpp
+++ b/main.cpp
@@ -1294,12 +1294,18 @@ int client_event_loop()
 				int recv_len;
 				struct sockaddr_in udp_new_addr_in={0};
 				socklen_t udp_new_addr_len = sizeof(sockaddr_in);
-				if ((recv_len = recvfrom(udp_fd, buf, max_data_len, 0,
+				if ((recv_len = recvfrom(udp_fd, buf, max_data_len+1, 0,
 						(struct sockaddr *) &udp_new_addr_in, &udp_new_addr_len)) == -1) {
 					mylog(log_error,"recv_from error,this shouldnt happen at client\n");
 					myexit(1);
 				};
 
+				if(recv_len==max_data_len+1)
+				{
+					mylog(log_warn,"huge packet, data_len > %d,dropped\n",max_data_len);
+					continue;
+				}
+
 				if(recv_len>=mtu_warn)
 				{
 					mylog(log_warn,"huge packet,data len=%d (>=%d).strongly suggested to set a smaller mtu at upper level,to get rid of this warn\n ",recv_len,mtu_warn);
@@ -1639,10 +1645,16 @@ int server_event_loop()
 
 				int fd=fd_manager.to_fd(fd64);
 
-				int recv_len=recv(fd,buf,max_data_len,0);
+				int recv_len=recv(fd,buf,max_data_len+1,0);
 
 				mylog(log_trace,"received a packet from udp_fd,len:%d\n",recv_len);
 
+				if(recv_len==max_data_len+1)
+				{
+					mylog(log_warn,"huge packet, data_len > %d,dropped\n",max_data_len);
+					continue;
+				}
+
 				if(recv_len<0)
 				{
 					mylog(log_debug,"udp fd,recv_len<0 continue,%s\n",strerror(errno));
diff --git a/network.cpp b/network.cpp
index 3c2181a..3c00a3f 100644
--- a/network.cpp
+++ b/network.cpp
@@ -704,7 +704,13 @@ int recv_raw_ip(raw_info_t &raw_info,char * &payload,int &payloadlen)
 	struct sockaddr_ll saddr={0};
 	socklen_t saddr_size = sizeof(saddr);
 	int flag=0;
-	int recv_len = recvfrom(raw_recv_fd, recv_raw_ip_buf, max_data_len, flag ,(sockaddr*)&saddr , &saddr_size);
+	int recv_len = recvfrom(raw_recv_fd, recv_raw_ip_buf, max_data_len+1, flag ,(sockaddr*)&saddr , &saddr_size);
+
+	if(recv_len==max_data_len+1)
+	{
+		mylog(log_warn,"huge packet, data_len > %d,dropped\n",max_data_len);
+		return -1;
+	}
 
 	if(recv_len<0)
 	{