I have a few domains on my server and I can reach all their websites. I was alerted that one of my domains was unreachable from Finland and after checking with siteuptime.com and alertra.com I see that that single domain is unreachable from Chicago and LA as well.

This domain is on the same server as my other domains, and is using the same registrar.

Where would the problem lie that would cause this one domain to be unreachable for the past few days?

The domain had resolved to our server a week ago, and the nameservers for the domain have been set correctly.

I checked MY nameservers in Registerfly and it claims they are not registered. According to LiveChat they are set to the right IP addresses (implying they are set correctly). I can not ping my nameservers (if they were down why is only one website unreachable in only two cities?).

Don't know but I have seen this happening on a few sites on different networks over the last few days.

Then it comes back for no reason. Something strange is going on with the internet. There is a thread on the cpanel forums on it also as other host are seeing it also.

run the domain through dnsreport.com and make sure there are A records for the nameservers.

[ERROR: The parent servers say that the domain ns1.clicheblog.com does not exist.]

I went to Registerfly before I did this and checked the status of my nameserver. It claimed that the server was never registered. I spoke with LiveChat about this and he was able to give me the correct IP's for the nameservers, which would imply that they do exist.

Also if the nameservers did not exist, then the domain shouldn't resolve at all, yet from FrankFurt, London and Detroit the name resolves (according to alertra.com)

08/14/2003 10:48:22 Frankfurt GERMANY OK 16819 1.31
08/14/2003 10:48:20 London UK OK 16820 1.36
08/14/2003 10:48:23 Los Angeles USA Unable to resolve na N/A 5.02
08/14/2003 10:48:20 Detroit USA OK 16820 1.15

As I said I have seen this a few times I have sights that have been up for months all on the same name servers all the sudden 5 out of 200 stop responding from only certain cities. dnsreport shows them clean. Then a few hours later they are back this has started happening only in the last week. Very sporadic.

Thanks, I did take a look at the cpanel forums and couldn't find the thread. Do have a link, or know what I should search for?

The MOST common problem I see is people not having A records for their name servers in their name servers. This WILL cause sporadic resolving with SOME name servers. I'm surprised how many "hosts" have this problem but blame ISPs for THEIR problem.