Multiple A records and reverse DNS
Bryan.Bradsby at capnet.state.tx.us
Tue Mar 22 16:01:38 UTC 2016
> That is mostly how I thought it worked. What I had in mind more
> specifically was:
> adi.com zone:
> mackerel.adi.com. IN A 22.214.171.124
> mackerel.adi.com. IN A 126.96.36.199
> reverse zones:
> 188.8.131.52.in-addr.arpa. IN PTR mackerel.adi.com
> 184.108.40.206.in-addr.arpa. (not yet set up)
OK, suppose you then set up
220.127.116.11.in-addr.arpa. IN PTR mackerel.adi.com.
That may not play well with all the SMTP servers you wish to send to,
due to subtle implementation variations.
> But receiving mail on both was more work than I had expected, so I am
> not going to set that up.
Many sites have separate incoming and outbound SMTP servers. There is
no reason to name them the same, especially not when you plan to
implement them on separate IP addresses/ranges.
The important thing is that the A and PTR records agree. That is most
simply done by using a single A record for each name, and a single PTR
record for each IP.
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