failover peer between 4.1 and 4.2.4

[sthaug at nethelp.no]

> Can I have a DHCP-Server 4.1 peer and a 4.2 peer, and will they work
> properly together?
> 
> (This isn't something I want long term, just a straightforward and easy way
> to upgrade from 4.1 to 4.2 by moving one server/peer at a time to 4.2.)

We had this for a short while for exactly the same reason. Zero issues,
everything just worked.

(The big issue is between 3.0.x and 3.1.x, where the format of the
messages between failover partners changed in an incompatible way. We
are past this now...)

Steinar Haug, Nethelp consulting, sthaug at nethelp.no