Max traffic inbound bind cap?. Absolutley bizzarie.

[Jens Doebler]

Hello Two Dog,

:

These machines are customer facing and see about 4 million queries an
hour or about 70,000 a min.  The majority of these about 45,000 being
A record lookups.

As with TCP/IP you can have roughly 64524 connections to an ip address.
Portnumbers are an 16-bit int and ports from 0 to 1024 are reserved for 
local applications.
So you can have 64524 connections to an ip address.
To check if that can be the problem make :
netstat -na | grep "<IP of the nameserver>:53" | wc -l You can subtract 
3 lines .

Other point you can check is the number of threads your os supports .
On sol9 check /etc/system for that .

That sounds like the most likely directions for me .

Greetings,

Jens