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Date: Thu, 13 Mar 2008 07:14:14 +0000 (UTC)
From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
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To: Mike Silbersack <silby@silby.com>
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Cc: freebsd-net@freebsd.org, "d.s. al coda" <coda.trigger@gmail.com>
Subject: Re: TCP options order changed in FreeBSD 7, incompatible with some
 routers
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On Wed, 12 Mar 2008, Mike Silbersack wrote:

>
> On Wed, 12 Mar 2008, Mike Silbersack wrote:
>
>> I think we will need to fix tcpdump before trying to finish diagnosing this 
>> problem.  We were missing key information before.
>> 
>> -Mike
>
> Hm, that was far easier than expected.  Patch attached.
>
> Here's what the two tcpdumps show now:
>
> 6.3:
> IP A > B : S 2575736483:2575736483(0) ack 1762868649 win 65535 <mss 
> 1460,sackOK,eol,eol>
>
> 7.0:
> IP A > B : S 3304309835:3304309835(0) ack 710421411 win 65535 <mss 
> 1380,sackOK,eol,nop>
>
> That makes the problem quite a bit more clear.  Anyone working on this issue 
> should apply this patch ASAP.

While this makes it more clear I'd rather see things in hex after the
first EOL but either way is fine, just to see it.

Ideally tcpdump would also complain if any padding after EOL is not
0x00.

I wonder if wireshark does?

-- 
Bjoern A. Zeeb                                 bzeeb at Zabbadoz dot NeT
Software is harder than hardware  so better get it right the first time.