How do I randomize the DNS source port number?

[Simon Waters]

phil-news-nospam at ipal.net wrote:
> 
> How can I make named randomize the source port it uses to send out
> queries when it's doing the recursion? 

I think only DJB's dnscache does this, of well known recursive
name servers.

> I think someone is doing a poison cache DoS on my server. 

Why do you think this? Have you identified what IP addresses are
sending all the packets? What version of BIND is running on the
recursive servers?

Cache poisoning isn't a DoS attack. You have to spoof a lot of
packets so it could look like one.