Eric A. Hall wrote:
On 10/23/2006 10:50 PM, John Rudd wrote:
Eric A. Hall wrote:
On 10/23/2006 7:01 PM, John Rudd wrote:
a) does the hostname in the PTR record point to a CNAME instead of an A
record
That's not illegal. It's pretty common too, since subnet delegation of
in-addr space only works on /8, /16 and /24 subnets due to the way that
octets are mapped to domain name labels in that hierarchy.
RFC 1912 says "don't do that" :-)
RFC1912 is informational non-authoritative. It has some big errors (ie, it
says a label may not be all-numeric, which is wrong).
Though, honestly, I've yet to see it actually get triggered in my
mimedefang filter, so I don't mind losing it.
Can you clarify what you are looking for here?
Note that this is entirely legal, and even necessary:
[ root# ] host 207.65.71.14
14.71.65.207.in-addr.arpa is an alias for 14.in-addr.ntrg.com.
14.in-addr.ntrg.com is an alias for 14.in-addr.labs.ntrg.com.
14.in-addr.labs.ntrg.com domain name pointer bulldog.labs.ntrg.com.
All of that's ok. The question is:
is bulldog.labs.ntrg.com an A record, or a CNAME record?
That's the thing I have been testing for (is it a CNAME). That's the
thing that RFC1912 doesn't like (the PTR record itself, not merely
in-addr.arpa aliases that eventually get to the PTR record, but the PTR
record itself, may not _refer_to_ a CNAME record, it must refer to an A
record)
