In <20040805161803(_dot_)GF28384(_at_)dumbo(_dot_)pobox(_dot_)com> Meng Weng
Wong <mengwong(_at_)dumbo(_dot_)pobox(_dot_)com> writes:
A common misunderstanding of DNS wildcards:
Another common misunderstanding of DNS wildcards:
Given
*.example.com TXT "blah"
foo.example.com A 192.0.2.1
Many people think that the wildcard will synthesize
bar.foo.example.com TXT "blah".
This is, however, not true.
You do get
bar.bar.example.com TXT "blah"
but you explicitly do not get a TXT record for bar.foo because
foo has an A record.
Yeah, I knew this, but forgot about it at the IETF meeting yesterday.
This was pointed out in the orignal SPF wizard where you needed to
have a bunch of wildcard statements to make it work. Apparently Meng
remembered but Mark, like I, forgot about this detail.
Really, DNS wildcards are almost completely useless.
-wayne