BIND 9.3.5-P1 random UDP src ports: some DNS responses delivered to wrong process

[Florian Weimer]

* Mark Andrews:

> 	Named doesn't just call bind(0.0.0.0#0) as many systems
> 	don't do good random port selection.  Lots of systems are
> 	sequential.  Linux keeps handing out the same port as long
> 	as it is not in use then sequentially increments it.

Linux 2.6.24 assigns non-sequential ports, but not from a PRNG which
should be considered strong enough (IMHO).

>       This can all be avoided if everyone signs their zones.
>
>       http://www.isc.org/sw/bind/docs/DNSSEC_in_6_minutes.pdf

I think part of our problem is that a presentation titled "DNSSEC in 6
minutes" consists of 77 slides. 8-)