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From: bert hubert <ahu@ds9a.nl>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] Weird problem, not 100% routing based.
Date: Fri, 07 Dec 2001 00:38:55 +0000	[thread overview]
Message-ID: <marc-lartc-100768557022147@msgid-missing> (raw)
In-Reply-To: <marc-lartc-100768091007540@msgid-missing>

On Thu, Dec 06, 2001 at 05:54:36PM -0600, Bill Williamson wrote:

Bill, please do not silently move discussions away from the mailinglist! I
am not a free consulting firm!

> > Run 'tcpdump -e -s 1500 -n -i eth0' while you try to connect to yourself
> and
> > supply us with the IP addresses. Replace eth0 with the right interface.
> 

Sanitized output of the tcpdump you provided:

5.4 a8:d7 1b:94  192.168.0.3.53395 > x.y.z.w.80: S 912730624:912730624(0) win 5840 <mss 1460,sackOK,timestamp 43698736 0,nop,wscale 0> (DF)
5.4 1b:94 a8:d7  x.y.z.w.53395 > 192.168.0.3.80: S 912730624:912730624(0) win 5840 <mss 1432,sackOK,timestamp 43698736 0,nop,wscale 0> (DF)

This part is good, your .0.3 host tries to connect to the external address, 
your router immediately sends a reply back, properly NATted.

5.4 a8:d7 1b:94  192.168.0.3.53395 > x.y.z.w.80: . ack 1 win 5840 <nop,nop,timestamp 43698736 43698736> (DF)

Linux doesn't go for it. It basically says 'I know this session already'!
This trace is all very very broken, and I think parts of it are missing.

I suspect that your router gets confused by timestamp and SACK options, but
I'm not sure.

Regards,

bert

-- 
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      parent reply	other threads:[~2001-12-07  0:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-12-06 23:18 [LARTC] Weird problem, not 100% routing based Bill Williamson
2001-12-06 23:25 ` bert hubert
2001-12-07  0:38 ` bert hubert [this message]

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