Strange DNS issue.
Posted on 2009-04-02
I have run across one that has stumped me and I am scratching my head trying to fix it. I have an AD domain with 2 DNS servers one is a backup to the other. There is a website that some of my users frequent that helps them do their work.
This website is accesible from some computers but not others. I started to track down the issue and realized that the address returns two different IP addresses when run against an NSLOOKUP. I have not only run it against my two DNS servers but also against my providers DNS servers and it always returns with the same two IP addresses. Which is not surprising since my DNS servers are doing lookups against my providers DNS servers.
What I can't figure out is why can some computers get to the site even though one of the ip addresses does not respond and other computers can't. I first thought it was a Vista issue only because by chance I had found that all the Vista computers I had been on could not get to the site but the few that I had tested that could get to it were running XP. I debunked that when I found a PC running XP that couldn't get to it as well.
Would creating a record for this domain on my DNS servers mitigate this problem?
I have flushed the DNS caches on all of the host machines that were not able to get to it and that did not help.
Any help is appreciated.