Subject: Re: [RFC/PATCH] "strict" ipv4 reassembly

From: Andi Kleen <[email-masked]>
Date: Tue, 17 May 2005 20:38:25 +0200

"David S. Miller" <[email-masked]> writes:

> From: Arthur Kepner <[email-masked]>
> Date: Tue, 17 May 2005 09:18:26 -0700 (PDT)
>
>>   1) Fragments must arrive in order (or in reverse order) -
>>      out of order fragments are dropped. 
>
> Even the most simplistic flow over the real internet
> can get slight packet reordering.
>
> Heck, reordering happens on SMP on any network.
>
> IP is supposed to be resilient to side effects of network
> topology, and one such common side effect is packet reordering.
> It's common, it's fine, and the networking stack deals with it
> gracefully.  Strict reassembly does not.

If anything it would be better as a per route flag.
Then you could set it only for your local network
where you know Gigabit happens and reordering might
be avoidable in some cases.

-Andi

P.S.: Arthur I think your arguments would have more
force if you published the test program that demonstrates the
corruption.