Here's the deal: On a fairly regular basis, I am unable to access my website, often for 5-10 hrs at a stretch. I use the same ISP at home and at work, and often can't reach the site from both, but sometimes just one or the other.

When I visit network-tools.com, I can ping, trace route, etc... the site using the domain name, so I know the site is "up", but I can only access it using the IP; the domain doesn't resolve.

I've been back and forth with the host and ISP trying to figure out what's going on. The ISP claims the following:

When their (ISP) nameservers try and access the site, it times out, and until they reload their cache, the site doesn't display for users of those name servers.

My host says this is BS as the NS "should go to root" to get the domain name if the nameserver is down (which they say it very rarely is).

What is going on? Our business is very local, and if a significant % of people here (only cable company in city) can't get our site...

Apologies if the technical stuff above is off base: I still don't quite grasp the lingo, but hopefully I've given a decent explanation of the problem.

Thanks!

It actually sounds like the ISP has it correct.

The host says that the ISP's dns servers should ask the root dns servers about the dns information if thier dns servers are down. This is wrong. The only information the root dns servers store is the name and IP address for the dns servers which have the "authoritive" information for a paticular domain name. So the ISP's dns servers are talking to the root servers and getting forwarded to the hosts dns servers. Which is likely where the timeout is happening.

Post or PM a domain name so someone can look at your DNS output. Might reveal a problem. Have to agree with whw as to where the problem exists.

Given the fact that your problems are intermittent, it sounds to me like either:

- your domain name has been transferred to at least one correct name server, and at least one wrong one as well. Do a WHOIS lookup on your registrar's site to see if the name servers are all correct and double-check with your host that the ones listed are the correct ones; or

- your domain name is pointing at the correct name servers but one of the name servers is misconfigured for your domain; or

- your host or ISP is having recurring problems with their DNS systems (hopefully less likely than the first two).

That is, the intermittent nature of the problem seems to indicate that when your ISP's systems try to look up the location of your site, sometimes they contact a name server with the correct information, and sometimes a name server with incorrect information. The most likely cause of that imho is that one of the name servers listed on WHOIS for your domain does not in fact return the proper address for your site.

Good luck :)

Try to ping the nameservers you've pointed the domain to.
One of them doesn't have "A" record I think.

If you cannot ping the nameserver contact your web host and ask them to configure the nameserver correctly. They must add "A" record for every nameserver and point it to correct IP.

We've had similar problems because of this reason.