DNS Cache not releasing

[Frank Hagan]

I have a new client who cannot seem to connect to his site on my server here. The name servers have propegated, and he knows that because one of his computers can see the new site, but the other two cannot. He is using FrontPage 2003, and cannot "publish" his "web" to the site, mainly because he cannot connect. He also cannot reach the site with Internet Explorer on the two machines.

One computer returns the right IP address when pinging his site, but the other two do not. Of the ones not reaching the site, one is running XP, the other XP Pro. I had him check his HOSTS files, and there was only the line for "localhost" in them, so I had him add his domain and the proper IP address. This was 5 days ago. Still no joy.

I asked him to do a "ipconfig /displaydns" and he gets the old IP address in his cache. After doing "ipconfig /flushdns", the entries with the old IP address remain in the cache. It is not "flushing".

We have cleared Internet Explorer cache as well. I am totally baffled by this. Is there somewhere else on a XP system using FrontPage that would cache the name server info?

[Pedja]

Check his /windows/system32/drivers/etc/hosts
Maybe he entered static entry in that file.

[Frank Hagan]

Check his /windows/system32/drivers/etc/hosts
Maybe he entered static entry in that file.

Yep, did that. I can get him pinging the right site on all computers now, but the ones with Frontpage on them won't "surf" to the right site, even in IE. I'm wondering if there's a link between FP and IE that is working in a circular manner. I asked him t DL Firefox to see if it will find the right site.

[Frank Hagan]

Well, we finally solved the problem, but I'm not sure it makes sense. My client finally got a call back from his ISP, and they said the DNS info had not updated on their side so they updated it, and he can reach the site now.

Is there a way to check an ISPs "TTL" (Time to Live) setting for their name server cache? It would have saved me a ton of time.

But, I'm still unsure why it sometimes resolved, but most of the time did not. Perhaps my client was just wrong about it ever resolving, or the ISPs cache sometimes was flushed but then reverted? I just don't see how it could happen this way. Any ideas?

[AndrewT]

ISP's have more than one DNS server, it is not out of the question that one may have updated before the other(s).

[Frank Hagan]

Actually, that would make sense then. Even when he would resolve to the new server, it was seemingly random.

[Buddha]

Is there a way to check an ISPs "TTL" (Time to Live) setting for their name server cache? It would have saved me a ton of time.

NSLookup. Your client may have to do it some ISP's DNS won't respond outside their network. ipconfig /all should tell you the ISP's DNS IP addresses.