diff --git a/srt/Packet.cpp b/srt/Packet.cpp
index 05050f23..cfcb6531 100644
--- a/srt/Packet.cpp
+++ b/srt/Packet.cpp
@@ -225,7 +225,35 @@ size_t ControlPacket::size() const {
 uint32_t ControlPacket::getSocketID(uint8_t *buf, size_t len) {
     return loadUint32(buf + 12);
 }
+std::string HandshakePacket::dump(){
+    _StrPrinter printer;
+    printer <<"flag:"<< (int)f<<"\r\n";
+    printer <<"control_type:"<< (int)control_type<<"\r\n";
+    printer <<"sub_type:"<< (int)sub_type<<"\r\n";
+    printer <<"type_specific_info:"<< type_specific_info[0]<<":"<<type_specific_info[1]<<":"<<type_specific_info[2]<<":"<<type_specific_info[3]<<"\r\n";
+    printer <<"timestamp:"<< timestamp<<"\r\n";
+    printer <<"dst_socket_id:"<< dst_socket_id<<"\r\n";
 
+    printer <<"version:"<< version<<"\r\n";
+    printer <<"encryption_field:"<< encryption_field<<"\r\n";
+    printer <<"extension_field:"<< extension_field<<"\r\n";
+    printer <<"initial_packet_sequence_number:"<< initial_packet_sequence_number<<"\r\n";
+    printer <<"mtu:"<< mtu<<"\r\n";
+    printer <<"max_flow_window_size:"<< max_flow_window_size<<"\r\n";
+    printer <<"handshake_type:"<< handshake_type<<"\r\n";
+    printer <<"srt_socket_id:"<< srt_socket_id<<"\r\n";
+    printer <<"syn_cookie:"<< syn_cookie<<"\r\n";
+    printer <<"peer_ip_addr:";
+    for(size_t i=0;i<sizeof(peer_ip_addr);++i){
+        printer<<peer_ip_addr[i]<<":";
+    }
+    printer<<"\r\n";
+
+    for(size_t i=0;i<ext_list.size();++i){
+        printer<<ext_list[i]->dump()<<"\r\n";
+    }
+    return std::move(printer);
+}
 bool HandshakePacket::loadFromData(uint8_t *buf, size_t len) {
     if (HEADER_SIZE + HS_CONTENT_MIN_SIZE > len) {
         ErrorL << "size too smalle " << encryption_field;
diff --git a/srt/Packet.hpp b/srt/Packet.hpp
index a226b588..fe56e236 100644
--- a/srt/Packet.hpp
+++ b/srt/Packet.hpp
@@ -189,7 +189,7 @@ public:
     static uint32_t getSynCookie(uint8_t *buf, size_t len);
     static uint32_t
     generateSynCookie(struct sockaddr_storage *addr, TimePoint ts, uint32_t current_cookie = 0, int correction = 0);
-
+    std::string dump();
     void assignPeerIP(struct sockaddr_storage *addr);
     ///////ControlPacket override///////
     bool loadFromData(uint8_t *buf, size_t len) override;
diff --git a/srt/SrtTransport.cpp b/srt/SrtTransport.cpp
index 0ef720f2..97d8f959 100644
--- a/srt/SrtTransport.cpp
+++ b/srt/SrtTransport.cpp
@@ -236,6 +236,7 @@ void SrtTransport::handleHandshake(uint8_t *buf, int len, struct sockaddr_storag
         handleHandshakeConclusion(pkt, addr);
     } else {
         WarnL << " not support handshake type = " << pkt.handshake_type;
+        WarnL <<pkt.dump();
     }
     _ack_ticker.resetTime(_now);
     _nak_ticker.resetTime(_now);