Re: [exim] which IP address will be used

Chump Chumpster wrote:
> Hi,
>
> I wonder if anyone can point me in the right direction? If I have a
> 'multi-homed' linux box i.e. with 2 IP adresses and I run Exim on it, which
> IP address will it use?

All IP it finds on the box unless told otherwise.

Tell it which one(s) to use in:

local_interfaces =

See also:

daemon_smtp_ports =

>
> Also, is it possible to set the IP address used by a parameter such as
> recipient domain? I'm thinking in the case of a local domain for a remote
> office that we have a 'peering' private network set up with. Maybe that's
> not a clear example, but could I route ourcompanydomain.com emails through
> one IP and everything else through another IP?
>
> thanks...

Possible, yes. Necessary? Perhaps not.

- if the *target* domain is to be reached over, for example, an internal LAN,
WAN, MAN or an external VPN, then short-circuiting the DNS lookup with a
'steering' entry in /etc/hosts ELSE a local, and 'preferred' DNS daemon might be
more flexible and easily changed/maintained than hard-coding it into Exim's
configuration - most especially if there are 'many' such in the pool and/or they
change frequently.

- if the source IP is (also) important, perhaps to make configuration of
(filters/rules) on the receiving servers easier to isolate between 'family' and
'strangers', then you will (also) want logic in the router/transport sets to do
some steering.

Plenty of examples in docs and archives...

Make sure you keep separate track of the Exim variables that apply to the
receiving IP (determined by what external DNS publish for your server) and the
sending IP (chosen by the configure file).

Bill