Re: [lwip-users] Handling sudden disappearance of network i/f

[Janusz U.]

> I've just had a look at how FINs are processed in the case of the
> netconn API.  The core lwIP will call the raw API recv callback with a
> NULL buffer.  This will post NULL to the netconn API's recv mbox.  The
> netconn_recv() function, when it gets NULL from the mbox, returns a
> length of 0.  This is standard semantics for "there are no more data to
> read".

you were right again. I checked by Ethereal. When I close socket on my 
serwer, the serwer doesn't send any packet like FIN. So lwIP is ok. Other 
programs can check the socket activity by keep alive.

thanks a lot.
Janusz