DNS server behind a firewall

Thanks a lot for the help and time spent on me!
I hope I understand the situation much better now :-)

To be fair, this occurred to be a headache to have
a windoops DNS server behind a Linux fw :-)
I guess only Mr. Gates knows why does a name server
initiates udp connections to addresses like 192.168.253.1
and 192.168.19.1 ...

Thanks once again to you and all other persons who
replied!

Regards,
Mikhail

In article <pDlxd.51287$DC.3054@fed1read03>, Gregory W Zill wrote:
> Bruno Wolff III wrote:
>> In article <jaPvd.4833$Sq.2775@fed1read01>, Gregory W Zill wrote:
>>
>>>The client may use whatever port it has free to initiate connection, but
>>>the RFC for DNS requires that is arrive on port 53. Therefore the rule
>>>is good as it stands 53 <-> 53.\
>>
>>
>> The above appears to be a contradiction, though perhaps I am misunderstanding
>> what 53 <-> 53 is supposed to mean. I assumed it meant the ports on both
>> sides of the connection are 53.
> No contradiction. A hardware firewall is in place between two network
> interfaces. The abbreviated rule or equation shown indicates that one
> (outside-facing) interface deals with the port on the left of the
> equation and the second (internal-facing) interface deals with the port
> on the right side of the equation. What port the client decides to
> initiate is not part of the equation, or the interfaces involved in
> setting up the firewall. This represents notation used by firewall admins.

OK, that makes sense.