In article <000701bf543f$f799fc40$0100007f@localhost>,
"Andrei V.Loukinykh" <[EMAIL PROTECTED]> writes:
> Hello
> I get these in syslog.
> And very often after that box is dead.
> Does this mean that someone tries to flood my sendmail queue?
> I've posted only 2 of such messages. There are much more usually.
> Dec 30 15:40:02 evp sendmail[83]: NOQUEUE: SYSERR(root): getrequests:
> accept: Co
> nnection timed out
> Dec 30 16:00:24 evp sendmail[83]: NOQUEUE: SYSERR(root): getrequests:
> accept: Co
No, these are completely normal (Linux accept does report errors, a lot
of other OS do not so sendmail's handling of it is a bit bogus) If the
box "drops dead" that would be a different bug. Unfortunately your mail
lacks all information (kernel version, what happens exactly, oops etc.)
that would be needed to diagnose it.
It could (there are lots of other possibilities) be the symptom of a synflood.
You can turn on syncookies to defend against them (echo 1 >
/proc/sys/net/ipv4/tcp_syncookies) assuming they are compiled in). For that
you should use at least 2.2.14 because they were broken between 2.2.11 and
2.2.13 (and kernels before 2.2.11 have other serious DoS bugs)
-Andi
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