Hello, I know a hostname can point to multi-IPs. but can an IP have multi hostnames in PTR? 164.0.217.172.in-addr.arpa. 86400 IN PTR mia09s16-in-f4.1e100.net. 164.0.217.172.in-addr.arpa. 86400 IN PTR ord38s42-in-f4.1e100.net. 164.0.217.172.in-addr.arpa. 86400 IN PTR yyz08s10-in-f164.1e100.net. this IP does seem like so. I never know this.
RFC 2181 would seem to cover this:
10.2. PTR records
Confusion about canonical names has lead to a belief that a PTR
record should have exactly one RR in its RRSet. This is incorrect,
the relevant section of RFC1034 (section 3.6.2) indicates that the
value of a PTR record should be a canonical name. That is, it should
not be an alias. There is no implication in that section that only
one PTR record is permitted for a name. No such restriction should
be inferred.
Thanks.
Attachment:
OpenPGP_signature
Description: OpenPGP digital signature