Re: Pb : Routing with multiples interfaces

[Hans van Kranenburg <od251@xs4all.nl>]

Frédéric Massot wrote:
> Hans van Kranenburg wrote:
>> Frédéric Massot wrote:
>> 
> [...]
>> 
>>> Thes Linux Box receives the internal mail on its internal
>>> interface. Postfix/Amavis/Clamav/Spamassassin check this mail and
>>> sends it on the LL interface ($INTERFACE_LL - $IP_LL).
>> 
>> Why don't you use the -o smtp_bind_address option in Postfix? Much
>> less complex setup... When Postfix chooses to bind to a specific
>> outgoing address the routing tables will follow that and choose the
>> right interface according to it.
>> 
> 
> This Linux Box receives the internal mail on its LAN interface and
> sends it on the LL interface. And it receives the external mail on
> these 3 external interfaces (DSL1, DSL2, LL) and sends it on the LAN
> interface. I think that I cannot bind the smtp daemon on LL
> interface.

Oh, and, by the way, you can direct mail to the LAN or to the LL by
creating an extra line in master.cf, like:

smtp    unix  - - - - -   smtp -o smtp_bind_address=add.re.ss.LL
smtplan unix  - - - - -   smtp -o smtp_bind_address=add.re.ss.LAN

And use the right one in the transport to direct outgoing mail to the
correct side of the firewall.

Defining two different smtp client processes has benefits because of the
connection caching algoritms in the newer postfix versions. It's also
possible to define different parameters like rate-limiting and max
concurrent connections between mail delivered to your internal
mailserver and mail delivered to the outside world.

The 'relay' transport (see master.cf) is also available for purposes
like this.

Hans