terry(_at_)ashtonwoodshomes(_dot_)com wrote:
-not all dns servers support "_"
Just for clarification: Which DNS servers do /not/ support underscores?
I know from testing that BIND 9 is happy with them; since Microsoft uses
them for some AD stuff, I guess that at least newer implementations of
their DNS services will not choke on them.
Local DNS libraries seem to be able to handle it - at least I haven't
heard of resolver-library incompatibility with products that use Apple's
Rendezvous, which is based on kind-of-SRV records and also use SRV's
_<service>._<proto> scheme.
Of course, further testing would be fine, but technically most relevant
pieces of DNS software around should not have issues underscores.
-many dns providers do not allow subdomains (or not easily via an interface,
and we need to keep
publishing easy or it won't get done)(yes I know many ISPs don't support TXT RR
either, but that
*is* changing and it *is* an RFC compliant DNS standard, even if SPF abuses it)
Which DNS providers do (not) allow subdomains and/or TXT records?
Adding something a record for "_spf" should not be any different from
adding a "www" record to a domain.
(Adding TXT records to the admin GUI of my non-profit ISP took me a
couple of minutes.)
IMO, there are no technical or admin issues for or against RR prefixes.
Having said that, there are of course policy reasons to consider - eg if
we go for a dedicated record type for "MARID", there is no need for a
prefix (after all, we don't have a prefix for MX records).
Still IMO, a prefix would only make sense if the TXT record workaround
were a long-term solution. As this quite possibly is not the intention
of this working group, using a prefix does not offer any benefits other
than possibly keeping the DNS response size below the magical 418 bytes,
a restriction which can be easily worked around using redirects by those
few(?) that would need it.
-- Matthias
--
Brain-Log http://matthias.leisi.net/