SYNCOOKIE authentication problems

[Julian Elischer]

Steve Kargl wrote:
> On Thu, Jun 28, 2007 at 02:50:40PM +0400, Eygene Ryabinkin wrote:
>> Steve, good day.
>>
>> Wed, Jun 27, 2007 at 06:43:11PM -0700, Steve Kargl wrote:
>>> Any advice on how to isolate or avoid?
>>>
>>> Jun 27 18:31:19 node11 kernel: TCP: [192.168.0.11]:59661 to 
>>> [192.168.0.11]:63266 tcpflags 0x10<ACK>; syncache_expand: Segment failed
>>> SYNCOOKIE authentication, segment rejected (probably spoofed)
>> According to Andre Oppermann, these are harmless:
>>     http://lists.freebsd.org/pipermail/freebsd-net/2007-June/014401.html
>>
>> But I am expiriencing some problems related to the other messages
>> like 'tcp_input: Listen socket: Spurious RST, segment rejected'.
>> Though it seems not to be your case, but my problems are documented
>> in the aforementioned thread.  Just in case you're curious...
>> -- 
> 
> Andre certainly knows more about TCP/IP than I, but no, these
> are not harmless.  Everytime one of these messages appears 
> on the console, my MPI application hangs and must be restarted.
> My large numerical simulations randomly die anywhere from
> 15 minutes to 25 hours after launching the job.

is the app on that machine or another machine?

>