Re: Virtual domains?

[Matti Aarnio <mea@nic.funet.fi>]

...
> Matti: what are the multiple IP addresses in the 2.99.38 config for,
> exactly? Does Zmailer not automatically bind to all addresses?

	The SMTP receiver does bind at all system IP addresses (by means
	of using a wildcard binding:  IP=0.0.0.0 port=smtp), however
	the transporter does need to know all IP addresses that the
	host does reply to, but there isn't any simple generic way
	to do it..  (Though  xntpd  does it, hmm...)

	The multiple addresses for the SMTP transporter are for it to
	detect local host IP addresses in case the mailer is running
	on a machine with virtual IP address other than the hosts real
	name knows about...

	That was created because the MTA switchover with a change to
	the DNS is rather slow process, and may take several weeks
	before all systems get the new addresses.  (Or so did our
	experience at change of  www.utu.fi  tell to us..)

	Thus we decided to change   mailhost.utu.fi  to be a "virtual"
	host that is bound to some real machine, as an IP-alias.
	Now the host itself does not have IP address of the mailhost
	bound to its addresses, but it needs to be conveyed to the
	smtp transporter so it can detect when it needs to drop MX
	entries pointing to itself (or other hosts with same or higher
	MX preference value)

	The entire thing was created to facilitate a quick move of the
	mailhost.utu.fi  without the need to touch on the DNS datasets.

> --
>  "Love the dolphins," she advised him. "Write by W.A.S.T.E.." 

	/Matti Aarnio <mea@utu.fi> <mea@nic.funet.fi>