Re: TCP connections to DJBDNS

Jakob Hirsch <[email protected]> Wed, 21 Jan 2009 01:00:36 +0100

Newsgroups	gmane.network.djbdns
Message-ID	<[email protected]>

Peter Dambier wrote:

> It is a must. If you do not support EDNS or if your clients dont
> support EDNS then you must support TCP.

That's not true. Though there is an implicit need for tcp (or EDNS0)
when your responses are going to be bigger than 512 bytes, and it's
probably good practice to offer tcp service, there is not general
"must". RFC 1123 says explicetely:

6.1.3.2  Transport Protocols
...
DNS servers MUST be able to service UDP queries and SHOULD be able to
service TCP queries.