A Record Synthesis From Address-like Domain Names (dnscache behaviour)

Unbound
1

Hi all,

I just finished moving all my caches to Unbound from dnscache, and loving it. It has so far two issues. Here's the most important question.

Dnscache has the habit of translating address-like domains into addresses, for the benefit of MTAs delivering mail to MX records containing IP addresses instead of hostnames. For example, the A record for the name '1.2.3.4.' is 1.2.3.4.

I know it's the world's worst hack of all time, but is there any way to get this with Unbound? I'd like to interoperate with such domains, until I can make them fix their zones. Yes, I will continue to look into making this possible with Postfix and XMail too, but DNS was a nice workaround.

Cheers,
Sabahattin

2

for the benefit of MTAs delivering mail to MX records
containing IP addresses instead of hostnames.

An MX record MAY not contain an IP address.

I know it's the world's worst hack of all time

Right.

(Perhaps you can implement a Python module in Unbound ... ?)

        -JP

3

In fact it MUST NOT :slight_smile:

My mail servers (40K users) treat domains that are misconfigured this way
as invalid and it does not cause noticeable interoperability problems.

Tony.

4

I think one of my earlier users may have turned to me for help precisely *because* your servers would not relay his mail. :slight_smile:

At any rate, fair enough, I'll just wait for the bounces to come in, and see how bad the problem really is. I only serve a few users (about 10) and many of them aren't non-English speakers natively which is where the problems really seem to be, with custom software running somewhere in the east.

Cheers,
Sabahattin