On Mon, 9 Aug 2004, Meng Weng Wong wrote:
I particularly do not want to see a world where the norm is:
example.com TXT "v=spf1 a mx ptr"
example.com TXT "v=spf2 a mx ptr"
Both records would contain the same content, yet senders
might feel the need to publish both "just to be on the safe side".
I'm torn between the "records really are validating different things so
they should have different version string" and the "keep the adoption ball
rolling" camps, but I am going to bring up a separate point here.
Forgive me if this snake has been addressed before, but at the WG meeting
last week it seemed to be slightly different. According to both folks
from Cisco and the in-house DNS experts I've asked, I believe that if you
put in multiple TXT records for the same FQDN (example.com as above), then
*all* of those TXT records are sent back in a single UDP reply packet, so
the 512 (more like 420) byte UDP packet restriction applies to THE
AGGREGATE SIZE of ALL text records for a single FQDN.
While the above example may be reasonably small, AOL's current SPF record
is pushing 170 bytes, which would limit them to publishing only three
concurrent records in the same FQDN space.
I believe that the working group made no objection to sub-domaining
records (publishing TXT in _marid.example.com), so if we go down the path
of changing the version number or even the format we should take that in