diff --git a/src/ipv6_assist/ipv6_assist_server.erl b/src/ipv6_assist/ipv6_assist_server.erl
index 75c2a5f..0387528 100644
--- a/src/ipv6_assist/ipv6_assist_server.erl
+++ b/src/ipv6_assist/ipv6_assist_server.erl
@@ -80,10 +80,13 @@ handle_cast(_Request, State) ->
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}.
 handle_info({udp, Sock, Ip, Port, Body}, State = #state{socket = Sock}) ->
+    logger:debug("[ipv6_assist_server] get request"),
     maybe
         ThrottleKey = {Ip, Port},
         ok ?= limit_check(ThrottleKey),
+        logger:debug("[ipv6_assist_server] get request11"),
         #'SDLV6AssistProbe'{pkt_id = PktId} ?= catch sdlan_pb:decode_msg(Body, 'SDLV6AssistProbe'),
+        logger:debug("[ipv6_assist_server] get request22"),
         V6Bytes = sdlan_util:ipv6_to_bytes(Ip),
         ReplyBin = sdlan_pb:encode_msg(#'SDLV6AssistProbeReply'{
             pkt_id = PktId,
@@ -92,6 +95,7 @@ handle_info({udp, Sock, Ip, Port, Body}, State = #state{socket = Sock}) ->
                 port = Port
             }
         }),
+        logger:debug("[ipv6_assist_server] get request33"),
         ok ?= gen_udp:send(Sock, Ip, Port, ReplyBin)
     end,
     {noreply, State};