cname quick question

[Jim Reid]

>>>>> "Erik" == Erik Aronesty <erik at primedata.org> writes:

    >> If a CNAME RR is present at a node, no other data should be
    >> present; this ensures that the data for a canonical name and
    >> its aliases cannot be different.  This rule also insures that a
    >> cached CNAME can be used without checking with an authoritative
    >> server for other RR types.

    Erik> Exactly.  How does having a CNAME at the zone-top cause this
    Erik> to be an error?  For that mater how does having an SOA
    Erik> record fail to allow cached CNAMES to be used without
    Erik> checking an authoritative server for other RR types?  It
    Erik> doesn't.  Because the SOA record is used for zone transfers
    Erik> and cache/timing information itself.  The RFC neglected to
    Erik> mention that.  That's all.

Like Tal Dayan, you are being obtuse or deliberately provocative.
Please *read* the extract from RFC1034 above. Now *think* about what
it says and what that means. Pay particular attention to the last
sentence. Hint: suppose clueless.example.com was a CNAME pointing at
moron.example.net. That CNAME is cached by some name server. It can
safely use that cached CNAME without having to query the example.com
name servers to check that no other record types exist for
clueless.example.com.

Now go away and please don't come back until the light switches
on inside your head.