On 15 Mar 2019, at 10:54, Jeremy Harris via Exim-users wrote:
> On 15/03/2019 14:36, Mike Tubby via Exim-users wrote:
>> Does the use of a CNAME in this case violate an RFC?
>
> I've not looked hard to find one. The original RFC
> for SRV doesn't mention CNAME.
It would not be feasible to prohibit a CNAME reply for a specific query
RRTYPE, since a CNAME has always been defined as applying to all queries
for a name. This is fundamentally different from the prohibition on the
RRDATA of a MX record being a name with a CNAME record.
FWIW, in this case it appears that there's a wildcard CNAME for
*.td3x.com, effectively pointing all non-existent names under that
domain to the parent name. That practice became fairly common as a
mitigation of the Verisign "SiteFinder" fiasco and other typo-hijacking
tactics.
--
Bill Cole
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(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
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