Re: Nslookup fails for external lookups

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From: Ace Fekay [MVP] (PleaseSubstituteMyActualFirstName&LastNameHere_at_hotmail.com)
Date: 07/17/04 

Date: Sat, 17 Jul 2004 10:25:36 -0400

In news:uHKsSX$aEHA.2408@tk2msftngp13.phx.gbl,
Kyle Heath <uce@cscm.co.uk> asked for help and I offered my suggestions
below:
> Yes I have a rule for the server to use UDP 53 send/receive and also a
> packet filter for DNS on the ISA Server itself.
>
> I can perform the lookups if I specify an external server, its just
> the forwarder on my DNS server that seems to timeout?
>

You'll need to allow TCP 53 as well, to get answers for some domains such as
AOL, Yahoo, Hotmail, etc, because their responses are large. UDP is used
when the packet size is below 512 bytes. If the answer is greater than 512,
the transport is changed to TCP. If using W2k3 DNS, it has a new feature
called EDNS0 which allows UDP packets greater than 512.

Give that a shot and let us know! 

-- 
Regards,
Ace
Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.
This posting is provided "AS-IS" with no warranties or guarantees
and confers no rights.
Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft Windows MVP - Active Directory
HAM AND EGGS: A day's work for a chicken;
A lifetime commitment for a pig.
-- 
=================================

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