DNS 2K3, initial page load, especially yahoo

[johnrmcc]

This annoying, yet elusive problem has been growing on us lately. 2 relatively new 2k3 dns servers in a 2k3 AD. When some users first open their browser, the page loads VERY slowly, but only for some users. Yahoo is the #1 culprit...anyone with that home page set, it may take 10 seconds or more to load, or just time out to page cannot be displayed. If you refresh, it instantly loads. If we temporarily change dns servers on the local machine to the outside forwarders...it loads instantly, so the problem is definately inside, in our dns. The lan is less than 50 users, all xp, and 2k & 2k3 servers, and a fast pipe. Any ideas? There were only 2 dns servers in our infrasticture, and we even disabled one temporarily and reset dhcp to reflect that. It seemed to correct the problem for a day or so, but its back again now.

 

[FaiTHLeSS]

Make sure all the Servers running DNS are pointing to themselfs ie 127.0.0.1. Make sure all clients are pointing to internal DNS servers only.

On the DNS console enable forwarders to point to your ISP dns servers make sure they are the correct IP's, it sounds like 1 of these IP's may be wrong in your settings causing slow lookups or time outs.

Remore root hints and just use fowarders.

 

[johnrmcc]

OK, let me just clarify....

IN tcp/ip settings...make sure the dns servers are pointing to themselves..ie 127.0.0.1 or their actual local ip...192.168.... Yes, this is being done already.

Forwarders are correct, and have been verified to work perfectly from outside our environment.

root hints...can these just be deleted from the dns console being that we are using forwarders? maybe the root hint for y (yahoo) is bad? actually i just checked and there are only root hints for a through m.

 

[FaiTHLeSS]

Delete root hints.

 

[FaiTHLeSS]

Oh and another thing try flushing the DNS cache.

Start > Run > Cmd > ipconfig /flushdns

 

[johnrmcc]

ya, we have been flushing dns cache to get a fresh start every time we make a change.

 

[johnrmcc]

ya, none of this has made a difference so far.

 

[johnrmcc]

now its worse...but it only seems to be for yahoo. what gives? does it have anything to do with the annoying way they do dns with akamai or whoever they use.

 

[FaiTHLeSS]

Is this affecting any other sites other than yahoo?

It sounds like a timeout issue between your DNS and your ISP DNS servers, have you tried using any other DNS servers instead of your ISP's?

 

[johnrmcc]

no, it really seems to be yahoo. i jumped around to a bunch of random sites, ones never visited before, and some others, and they come right up. and we have no caching device or proxy running either. its basically our dns, fwd to isp dns, out to site and back. after deleting the root hints, i cant even load yahoo now, flushed dns and all.

 

[FaiTHLeSS]

Sounds like there may be a problem with your forwarders or it could just be that some of yahoo sites are having problems if other sites are loading fine.

It it yahoo.com ? if so try yahoo.co.uk or another countries yahoo because the servers are located all over the world.

Im running out of ideas now to what the problem could be, especially since other sites are working ok.

 

[johnrmcc]

ya, its just yahoo...so get this...i can telnet to yahoo's ip address on port 80 just fine, but both mozilla and ie wont load the content.

 

[FaiTHLeSS]

im really stumped, i cant think what is causing it, unless there is some sort of routing problem, but then you would have problems telneting to it.

 

[johnrmcc]

yea, i am stumped, and so are the guys at my isp, even the guy i consider to be really good. here's a twist though...in the properties of dns on the forwarders tab...I have 3 forwarders and the "# of seconds before a query times out" was set to 5. i changed that to 1, flushed dns and so on, and now it loads, sometimes a little slow, sometimes instantly. What is standard for that setting?

 

[FaiTHLeSS]

I have mine on default which is 5. Try changing the order of the DNS forwarders servers see if that makes a change. It seems that its getting an answer maybe from the 2nd or 3rd server but not the 1st.