Bind on strange UDP ports?

[Cricket Liu]

> Ok I've never really noticed this behavior before.. But I am seeing it on
> a few servers..
>
> Bind is binding to the ports specified in the named.conf, port 53.. UDP
> and TCP.
>
> It is also binding on a high port.. like 4431 UDP. Then if you ndc reload
> it steps up one port to 4432.. Sometimes it skips a few.. Up to like
> 4437.. then another ndc reload it ups to 4438. And so on. Well this causes
> a problem.. It binds to EVER interface, even if you have the named.conf
> telling it to only bind on one interface.
>
> What is this UDP port.. How do you get rid of it.. and why is it
> there.. and not in any documentation? (Or is it?)

It's probably the query port.  BIND 8 name servers send queries
from a high-numbered port.  They bind() to it at startup and, I guess,
after reloads.

cricket