Subject: Re: ProxyARP and IPSec

From: David Miller <[email-masked]>
Date: Fri, 22 Sep 2006 13:36:46 -0700 (PDT)

From: Alexey Kuznetsov <[email-masked]>
Date: Tue, 5 Sep 2006 13:05:30 +0400

> Look into old rfc2401, search for word "fragment".
> Then search for the same word in new rfc4301. All those 100K of new text
> deal with various design bugs in IPsec, mostly with pathologies encountered
> in the case of security gateways. (Some section there are real fun: f.e.
> look at section 7.2)

I even was not aware of this problem. :-)

Essentially, if you use ports as part of your selector,
then it is impossible to handle anything other than the
first fragment of a fragmented frame because the subsequent
fragments will not have the ports which you need in order
to match.

The suggestions in 7.2 involving a seperate SA for the non-first
fragments seem totally unrealistic, if you ask me.  They even say
the idea cannot work with ipv6, what is the point? :-)