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?