Just ran a dns report on http://www.intodns.com for one of domains thats using the Linode DNS..

Its come up with the following error..

FAIL: The following nameservers are listed at your nameservers as nameservers for your domain, but are not listed at the parent nameservers (see RFC2181 5.4.1). You need to make sure that these nameservers are working.If they are not working ok, you may have problems! 
ns5.linode.com

and

Stealth NS records were sent: 
ns5.linode.com

What would be causing this?

Try it on your domains and see if you get the same..[/code]

Did you list ns5.linode.com as one of your nameservers at your registrar?

I see the same error.

My domain registrar though doesn't have room for more than 4 NS records, so I have ns1 through ns4 listed there.

Is there any issue with not having the 5th listed at my registrar? Besides the obvious conclusion that if ns1-ns4 are down, I don't have DNS for my domain.

Mine is the same.. I only have the option for 4 name servers in my domain configuration..

Not sure what the effect of this would be but by the error it makes it sound like there must be some issue by the word "FAIL" in the message..

It's not a huge deal; I certainly wouldn't label it a "FAIL". It just means that one fewer server is listed as authoritative for your zone at the registry. If {ns1...ns4} went down and ns5 stayed up, you'd be out of luck, while someone with the full delegation would still resolve (although quite possibly in a slow and/or flaky fashion, depending on the nature of the outage, and client implementations).

Having the registry server and the zone-authoritative server not quite agree on the nameserver list isn't exactly pretty, but it won't cause any real-world problems beyond the above scenario.

In other news, if your registrar isn't letting you set more than four nameservers, it's time to find a new registrar.

I think most people would think that 4 would be enough.. At least thats the case with the developers of WHMCS..

The domain I tested is managed through WHMCS which only has 4 NS fields..