Subject: Re: can't sup
To: None <>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
List: current-users
Date: 07/08/1994 08:47:07
>>>> I haven't been able to sup since yesterday; I get "connection
>>>> timed out" when trying to connect to sun-lamp, but sun-lamp is
>>>> obviously up (I can ping/telnet to it fine from my machine)
>> FTP, SMTP, ping all seem to work okay, just not sup :-(
> Me too.

> for example:

> telnet smtp
> telnet supfilesrv
> 	Trying...
> 	telnet: connect: Connection timed out

> "Connection timed out" is something strange, because if supfilesrv
> dies, It should be "Connection refused".

This usually indicates that the daemon serving new connections (the one
doing the accept(2)s) is hung, and the socket's queue of new
connections is full.  (This queue's size is the parameter to listen(2),
and the kernel usually silently puts a hard maximum, typically 10, on
it.)  Really old kernels (such as, I think, pre-Tahoe 4.3) will refuse
the connection when this happens; newer ones just ignore the packet and
hope that some pending connection will have been accepted by the time
the retransmit arrives.  Of course, since supfilesrv is completely
wedged, it's never going to accept any new connections, so all
retransmits are also dropped, and you get ETIMEDOUT.

					der Mouse