Re: [Exim] Mail routing and backup question.

On Thu, Dec 21, 2000 at 02:46:28PM +0000, Philip Hazel wrote:
> This would cause your Exim to route some.random.domain to itself. It
> doesn't, because it checks the IP address.

OK, maybe I asked the question slightly wrong, or I don't understand
the answer - more likely.

According the "DNS and BIND, 3rd Edition" MX records must be canonical
host names, because sendmail (and RFC written to document sendmail's
behaviour I guess) say that a mail host compares MX records to it's own
name - not IP address - and uses that as a rule to check if it should
relay onward to any lower MX host.

Are you saying that exim does not do this ?

If so, great :-)

> Doing this has proved a pain because the functions for determining all
> the local addresses vary between OS. IRIX has a completely different
> interface, but eventually somebody produced some code for that system.

UNIX and UNIX-like systems are completely compatible. Didn't someone
tell you this ? Next you will be telling me that the API / kernel
interface to routeing tables is not uniform ;-)

> As well as checking by IP address, there is some checking by name.
> hosts_treat_as_local is a list of such names.

Should I then list all my (reverse)CNAMEs here normally ? Seems like a sensible idea anyway, even if lookup is by IP.

Thanks and a Merry time-of-year to all,
--
Peter