Multiple PTR records
Mark.Andrews at nominum.com
Mark.Andrews at nominum.com
Thu Jun 7 22:59:15 UTC 2001
>
> To clarify: there is nothing in the DNS protocol to stop you from creating mu
> ltiple
> PTR records with the same name, however no app is known to actually look beyo
> nd the
> first PTR in a response, and because of this fact BIND suppresses RR sorting
> for
> PTR records. So essentially all PTRs beyond the first one are "invisible" and
> a
> waste of packet space (if the response overflows the 512-byte limit, then it
> may
> also waste TCP retransmissions too).
>
>
> - Kevin
Some site even go so far adding PTR records that they exceed
the protocols ability to send them in a response. I wonder
about sites that do this and how much else they don't know
about.
You could even use multiple PTR records as a filtering
critera when selecting web hosting providers. If they list
multiple PTR records then they most probable don't know
what they are doing and you should shy away from them.
It sound like you are trying to learn what to do which is
good. Good luck and keep up the learning.
Mark
--
Mark Andrews, Nominum Inc.
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: Mark.Andrews at nominum.com
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