John R Pierce wrote:
Les Mikesell wrote:
Mail isn't supposed to be rejected for this, but some places probably
do. A more correct approach is to have one name with the A record and
the matching ptr and make all of the other names CNAMEs.
no, no, no! CNAMES are discouraged as they create additional work
for everyone else's DNS servers.
Is there an RFC to that effect? I didn't realize DNS lookups were a
scarce resource.
the only time its proper to use a
CNAME is when you are referencing a host on someone else's network who's
addressing and management is beyond your control and you won't get
notifications if its changing.
I suppose something like this is overkill, though...
Non-authoritative answer:
www.redhat.com canonical name = www.redhat.com.edgekey.net.
www.redhat.com.edgekey.net canonical name =
www.redhat.com.edgekey.net.globalredir.akadns.net.
www.redhat.com.edgekey.net.globalredir.akadns.net canonical name =
e86.b.akamaiedge.net.
Name: e86.b.akamaiedge.net
Address: 64.215.167.112
for email, all the various domains should have MX records with the mail
server's "true" name.
MX records don't have much to do with the system sending mail.
--
Les Mikesell
lesmikesell@xxxxxxxxx
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