RE: Configure postfix in big env

10 msg	header check question
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Configure postfix in big env
\ Sebastien.Dicque (9 May 2008)
. \ Brian Evans (9 May 2008)
. . \ Jason Ledford (9 May 2008)
. . . \ Bill Cole (9 May 2008)

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Subject:	RE: Configure postfix in big env
Group:	Postfix-users
From:	Bill Cole
Date:	9 May 2008

At 9:43 AM -0400 5/9/08, Jason Ledford wrote:
>Not all load balancers. http specific load balancers (pen, haproxy,
>...) do only forward the load balancer ip. But you can using lvs
>(linux virtual server) and it can forward the originating ip.
>Lvs-nat could be compared to cisco local director (except in price),
>others can do similar things, like f5 and zeus load balancers, all
>come at a price except lvs.

FWIW, the F5 Big-IP can go either way.

I wouldn't put load balancers of any sort on the public-facing side
of any mail system, but load balancing can be very useful when done
robustly (i.e. the load balancers are themselves redundant rather
then a single one being a SPOF) to coddle naive/stupid/simple systems
that want to send mail but can only handle a single smarthost model.

> I am doing smtp load balancing right
>now with lvs-nat and its working like a champ. The outside and the
>real servers have no clue that the load balancer even exists.

That begs the question: why?

For all but the very largest mail systems, DNS-based load sharing via
multiple same-value MX records pointing at names that may have
multiple A records gets the load balance and availability jobs done
without the extra layer.

--
Bill Cole
bill