We introduce the forward lookup operator consistency, adding PTR-records can only increase the chances that the check will fail.
In contrast, adding A records can only increase the chances that the check will succeed. Note: In what follows, we assume you are using the ISC "bind" daemon (aka “named”) as your DNS server.
Alas, these daemons do not appear to be smart about multiple A records, let alone multiple PTR-records. In theory, part of the problem could be solved by adding the appropriate interface names to the /etc/dhcp3/file.
Reverse dns records not updating
If you try it, any attempt to ifup one interface brings up the other also.
Simiilarly, any attempt to ifdown one interface brings down the other also.
Here is a little script to check DNS records for consistency. When a lookup returns multiple results, the default server behavior is to return them in a different order each time.
Given a numeric IP address, it checks for strong #! This is probably what you want for forward lookups, especially if you want load-balancing, ...
There are several types of consistency check that we could make.
We can clarify the situation by introducing a little bit of notation.
(An example is mentioned in section 4.) If the DNS and r DNS records are not consistent, the recipient is likely to not accept the message, which is going to make the sender very unhappy.
For this reason, most organizations are fastidious about the DNS records for their mail servers, even if they neglect their other servers.
It is important for DNS records to exhibit certain types of consistency.