[dns-operations] A problem with using DNAMEs in reverse lookups

Anand Buddhdev anandb at ripe.net
Sun Apr 3 08:36:20 UTC 2011

On 03/04/2011 10:19, Jeroen Massar wrote:

> Mail servers are just broken per DNS, even postfix does not properly
> contact the right MXs, it connects to every single address of an MX
> before going on to the next, even though the MX might respond with a
> 3xx/4xx/5xx style response it will keep on connecting to the other AAAA
> or A records, while it should give up on the MX and try the next MX instead.

That's debatable Jeroen: an MX record's multiple addresses may in fact
be _separate_ machines, so I can argue that postfix is doing the right
thing. That's my opinion anyway.


Anand Buddhdev

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