[erlang-questions] Re: tcp_close during async accept

Javier París Fernández <>
Wed Jul 8 23:42:55 CEST 2009


El 08/07/2009, a las 18:27, Joel Reymont escribió:
>
> I'm reconnecting after a random delay when this happens. I was  
> wondering why it's a successful connection on the client side and  
> then a tcp_close since it's not even getting to the Erlang accept on  
> the server side.

The easiest way to debug these kind of errors is to have a look at the  
actual packet trace with a sniffer. Look at wether the server is  
sending syn+acks to all the connection attempts. You can also look for  
rst that may explain that "open in the client but immediately close"  
behaviour.

Regarding what Oscar suggested about syn cookies, they are indeed a  
syn flood prevention technique, but they do not actually drop any  
connection so even if it is being used here it should not be an issue.  
You can guess if it is indeed used by the server if you see that some  
of the syn+acks replies it sends do not have any tcp option.

Regards.



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