[erlang-questions] Erlang udp server can't receive accept packets

yuzhu chen billcyz@REDACTED
Mon May 15 11:27:56 CEST 2017

I've posted the same question on stackoverflow, but haven't got answers
yet. So I posted this question again in here hoping for a solution.

down votefavorite

I have one simple udp server written in gen_server behaviour. When I run
it, and try to send message by using gen_udp:send, the server replies
nothing, seems like the udp server didn't accept packet successfully. Here
is my code


handle_call/3, handle_cast/2, handle_info/2, terminate/2,
-define(SERVER, ?MODULE).
-record(state, {socket,

start_link(Port) ->
    {ok, Socket} = gen_udp:open(Port, [binary,
                                       {active, false},
                                       {reuseaddr, true}]),
    gen_server:start_link(?MODULE, [Socket, Port], []).

init([Socket, Port]) ->
    {ok, #state{socket = Socket, port = Port}}.

handle_cast(_Request, State) ->
    {noreply, State}.

handle_call(_Request, _From, State) ->
    {noreply, State}.

handle_info({udp, _Socket, _Addr, _Port, Data}, #state{socket =
Socket} = State) ->
    inet:setopts(Socket, [{active, once}]),
    io:format("Server received data ~p from socket ~p~n", [Data, Socket]),
    {ok, State}.

terminate(_Reason, {socket = LSocket}) ->

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

Starting server on server gen_udp_server:start_link(10000).

Sending message from

{ok, Socket} = gen_udp:open(4399, [binary, {active, false}]).
gen_udp:send(Socket, {192,168,146,129}, 10000, "hello").

The udp server should print some message when it receives packets, but my
one failed. Can anyone help me?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20170515/a344daef/attachment.htm>

More information about the erlang-questions mailing list