My web host does not use DNS over TCP?

[joxocafeco]

Hi
I tried the Pingdom DNS test on my website, and it says that my host nameserver does not answer DNS over TCP.
I contacted my host and they said that they use DNS over UDP, so TCP is not needed.
Am I missing something here? As far as I learnt, TCP is a requirement, always. Right?

[kpmedia]

DNS only uses TCP in certain circumstances -- not typical IPv4 DNS usage.

Quote:

Originally Posted by http://en.wikipedia.org/wiki/Domain_Name_System#Protocol_transport

DNS primarily uses User Datagram Protocol (UDP) on port number 53 to serve requests.[3] DNS queries consist of a single UDP request from the client followed by a single UDP reply from the server. The Transmission Control Protocol (TCP) is used when the response data size exceeds 512 bytes, or for tasks such as zone transfers. Some resolver implementations use TCP for all queries.

However...

TCP is needed for the age of IPv6 and DNSSEC.

So your host is (maybe) fine for now, but they're not future proofed.

Questions:
1. What is you domain? Look it up via the intodns.com tool.
2. Who is the host? -- And what are they using for their DNS clustering, if known?

[joxocafeco]

I looked up the domain via Pingdom's DNS tool and that's where it gave the error.
The host is StableHost, they told me they are using it over UDP so TCP is not needed?

[kpmedia]

Well, I'm guessing you have shared, reseller or enterprise hosting with Stablehost, yes? That means you're using their DNS cluster. They're not using anything "fancy" like IPv6 or DNSSEC yet (because cPanel does not support it). So in your case, yes, UDP-only port 53 under-512kb packets for DNS is fine. TCP is not needed.

If you had your own custom server, then it'd be a different story.

Make sense.

You're fine.

[joxocafeco]

Yes, reseller and enterprise it is.
Thanks for the clarification.