Failover without shared-network?

[Simon Hobson]

Ken Roberts wrote:

>I have a server version 3.0.3-r9 running on an up-to-date Gentoo system
>which uses a 2.6 kernel.  It's an office setting with a set of Cisco
>layer 3 switches using approximately 10 VLANs, which are separate
>physical networks that map to subnet constructs in the dhcp
>configuration file.  This configuration works exactly the way I want it
>to.
>
>Now, the problem.  I need to set up failover.
>
>The documentation says I need a shared-network construct around
>everything that is to have failover service.

Where, I don't see that ?

>   It further says that
>inside a shared-network construct all the pools are jumbled together and
>handed out randomly.  That's paraphrasing of course.

Correct

>In my understanding, shared-network means that several subnets are
>sharing the same physical network.  This is not the case for me, but the
>Cisco gear is using an ip helper-address that points to my DHCP server,
>and forwards enough information that my clients get addresses that are
>appropriate to the VLAN.
>
>The question here is, what is that shared-network construct going to do
>to me?

It would totally screw you up ! You do NOT want to do shared-network 
if you don't have one.

Simon