Segment failed SYNCOOKIE?

Steve Kargl sgk at troutmask.apl.washington.edu
Tue May 29 00:24:49 UTC 2007


On Mon, May 28, 2007 at 05:31:18PM +0200, Andre Oppermann wrote:
> Steve Kargl wrote:
> >Anyone have ideas on how to cure
> >
> >May 25 16:20:03 node13 kernel: TCP: [192.168.0.15]:53815 to
> >[192.168.0.13]:50992 tcpflags 0x11<FIN,ACK>; syncache_expand:
> >Segment failed SYNCOOKIE authentication
> >
> >The hardware and kernel on 192.168.0.15 and 192.168.0.13
> >are identical.
> 
> Do you have any daemon listening on [192.168.0.13]:50992?
> 

I've set "net.inet.tcp.syncookies=0" in /boot/loader.conf
to disable syncookies.  I'm now seeing 

> May 28 16:39:59 node13 kernel: bge0: watchdog timeout -- resetting
> May 28 16:39:59 node13 kernel: bge0: link state changed to DOWN
> May 28 16:40:02 node13 kernel: bge0: link state changed to UP
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.13]:62460 to
> [192.168.0.13]:56460 tcpflags 0x10<ACK>; syncache_expand: Spurious ACK
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.13]:64274 to
> [192.168.0.13]:49985 tcpflags 0x10<ACK>; syncache_expand: Spurious ACK
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.11]:51473 to
> [192.168.0.13]:57885 tcpflags 0x11<FIN,ACK>; syncache_expand: Spurious ACK
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.12]:49393 to
> [192.168.0.13]:57885 tcpflags 0x10<ACK>; syncache_expand: Spurious ACK
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.12]:61494 to
> [192.168.0.13]:52887 tcpflags 0x10<ACK>; syncache_expand: Spurious ACK
> May 28 16:41:51 node13 kernel: TCP: [192.168.0.12]:63379 to
> [192.168.0.13]:63472 tcpflags 0x10<ACK>; syncache_expand: Spurious ACK

This is occurring with an openmpi application.
-- 
Steve


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