RE: Interesting problem...
- From: "Jim Harrison" <Jim@xxxxxxxxxxxx>
- To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
- Date: Mon, 28 Feb 2005 06:21:46 -0800
Hi Dan,
Actually, it does.
ISA doesn't care how you've built your LAN.
What it does care about is that if a host wants to cross its boundaries,
the ISA policies allow it.
Using the root servers isn't unexpected if your LAN DNS servers aren't
"root" themselves.
If the PDC is also your primary LAN DNS server and it needs to perform
root lookups, then it also needs to be part of the DNS access policy.
Another way to get around this is to install a caching DNS server on the
ISA itself and let the LAN DNS servers forward to it.
-----Original Message-----
From: Ball, Dan [mailto:DBall@xxxxxxxxxxx]
Sent: Monday, February 28, 2005 5:33 AM
To: [ISAserver.org Discussion List]
Subject: [isalist] Interesting problem...
http://www.ISAserver.org
I've finally got most of the slowness out of our Internet access,
everyone was convinced it was due to our ISP, but I had suspicions when
our own published webserver was also slow. Based off of past
experiences, I kept looking at DNS as the most likely culprit, and I was
correct.
I have DNS servers installed on all our DCs, and only the PDC has
forwarding addresses in it, as that is the one that is supposed to
resolve all unknown addresses. While troubleshooting this slowness, I
couldn't find anything wrong, as all DNS queries appeared to be passing
through correctly. After awhile, I decided to again do an ISA log
search for DNS queries, but left the PDC off the filter (not sure why I
didn't do this to start with). I found that the second DNS on the local
subnet was attempting to resolve addresses using a whole bunch of
different IPs. After looking a little further, I realized that all of
the addresses it was attempting to reach were the "root hint" sites.
So, it was a simple fix, I just added the other DNS server to the policy
allowing DNS to pass through, and everything started to run slightly
faster. However, this doesn't really explain what exactly is wrong,
there does appears to be some sort of miscommunication between the DNS
servers.
Anyone have any idea where to start looking? I can't see anything
wrong, other than looking at the logs on the ISA server, everything
seems to be working fine.
------------------------------------------------------
List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist
ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp
ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ
------------------------------------------------------
Other Internet Software Marketing Sites:
World of Windows Networking: http://www.windowsnetworking.com
Leading Network Software Directory: http://www.serverfiles.com
No.1 Exchange Server Resource Site: http://www.msexchange.org
Windows Security Resource Site: http://www.windowsecurity.com/
Network Security Library: http://www.secinf.net/
Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com
------------------------------------------------------
You are currently subscribed to this ISAserver.org Discussion List as:
jim@xxxxxxxxxxxx
To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=isalist
Report abuse to listadmin@xxxxxxxxxxxxx
All mail to and from this domain is GFI-scanned.
Other related posts: