How do you know when a socket disconnects

[DaTurk]

I want to know when a socket disconnects so I can attempt to reconnect.
Is there any special type of pattern to doing this? Is there an evnt
raised?

[Ben Voigt]

"DaTurk" <mm******@hotmail.com> wrote in message
news:11**********************@f6g2000cwb.googlegro ups.com...

I want to know when a socket disconnects so I can attempt to reconnect.
Is there any special type of pattern to doing this? Is there an evnt
raised?

If the other endpoint sends RST, you will get an error the next time you
call any read or write function. If the network breaks (remote endpoint
rebooted, too many lost packets, whatever), then TCP typically retries for
an extremely long time (less and less frequently) without ever determining
the connection is lost. Many TCP-based protocols have keep-alive and
timeout for this reason.

[DaTurk]

Thanks for the reply, so if I wanted to know when a socket disconnected
so then I could reconnect for a certain amount of times, how would one
do this. I can't really find anything about it.

Ben Voigt wrote:

"DaTurk" <mm******@hotmail.com> wrote in message
news:11**********************@f6g2000cwb.googlegro ups.com...

I want to know when a socket disconnects so I can attempt to reconnect.
Is there any special type of pattern to doing this? Is there an evnt
raised?

If the other endpoint sends RST, you will get an error the next time you
call any read or write function. If the network breaks (remote endpoint
rebooted, too many lost packets, whatever), then TCP typically retries for
an extremely long time (less and less frequently) without ever determining
the connection is lost. Many TCP-based protocols have keep-alive and
timeout for this reason.

[DaTurk]

Will a asynch receive receive 0 bytes when the socket closes? Would it
be possible to use that as an indication?

[Markus Stoeger]

DaTurk wrote:

Will a asynch receive receive 0 bytes when the socket closes? Would it
be possible to use that as an indication?

The Receive functions return 0 bytes to indicate that a connection has
been closed. Take a look at the MSDN help page for Socket.Receive. You
should also put a try/catch around the whole thing.

hth,
Max