TXT record

[Kevin Darcy]

Kenneth Porter wrote:

> I've seen mention of TXT records on the list recently, but have never
> encountered one. What are they for? (I know about SOA, NS, A, CNAME,
> PTR, MX, HOST, and LOC. Just not TXT.) Is there a doc somewhere (RFC?)
> that lists all the kinds of records and what they are?

As others have mentioned, TXT records just store arbitrary text data, and
their format is defined in RFC 1035. The only thing I'd add is that there
have been various proposals over the years to "structure" TXT records to
store various kinds of information (see generally RFC 1464, for moves in
that direction). The general consensus seems to be that this is a Bad
Idea. Those proposals have gone nowhere. Either the data is so important
and relevant that it deserves its own record type, or it doesn't belong
in DNS at all, more properly to be stored in an LDAP-accessible directory
or something like that. So if you're considering using TXT fields as a
kind of "meta-database" within the DNS database, I'd say follow the
received wisdom of the protocol gods and seriously consider using some
other repository instead (not that the received wisdom is always *right*,
of course, but it does bear serious consideration and respect). If you're
not considering any such thing, then at least this might help explain why
TXT records are extremely rare...


- Kevin