Failover without shared-network?

[Ken Roberts]

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

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?  I do NOT want any of the stuff described in the docs to be done
to my network.  Is there some way to get around that, or is there
something in the works to enable failover without a shared-network?

Thanks.