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Date: Fri, 03 Apr 2009 09:02:29 -0700
From: Julian Elischer <julian@elischer.org>
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To: Luiz Otavio O Souza <lists.br@gmail.com>
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Cc: freebsd-hackers@freebsd.org, Lawrence Stewart <lstewart@freebsd.org>
Subject: Re: Setting the mss for socket
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Luiz Otavio O Souza wrote:
>>> Is there a way to set the mss for a socket ? Like you can do
>>> in linux with setsockopt(TCP_MAXSEG) ?
>>>
>>> So i can set the maximum size of packets (or sort of) from a
>>> simple userland program.
>>
>> Depending on exactly what you need to accomplish, you may
>> find something useful in this thread from last August in
>> freebsd-questions@
>>
>>  setting the other end's TCP segment size
> 
> Very informative thread, thanks.
> 
> This thread show me that TCP_MAXSEG is implemented in freebsd but don't
> work. You can set the setsockopt(IPPROTO_TCP, TCP_MAXSEG), wich will set 
> the
> tp->t_maxseg, but this value is recalculated at tcp_input, so in short, you
> cannot set the max segment size for a socket.
> 
> I've posted a completly wrong patch (from style point-of-view - and using
> SOL_SOCKET instead of IPPROTO_TCP), but with that patch i'm able to set the
> mss in iperf.

this thread shoud be in FreeBSD-net@ so tha the right people see it
many developers do not read hackers every day as it tends to overload 
them.

> 
> Many thanks,
> Luiz
> 
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