Cisco's require the ip subnet-zero global configuration command
in order to accept the all zeroes subnet.
> So splitting a Class C in half for use with a firewall is a
> perfectly fine thing to do. RFC 950 was written TEN YEARS AGO,
> when there was spare IP address-space to burn.
>
Yep, done it many times.
> There appears to be a lot of confusion over PortMasters and netmasks,
> but there's one simple rule that should make it easier to understand:
> All our products support ONE netmask per network. We expect a network
> to be sliced up the same way, which is another way of saying that we
> don't do variable length subnet masks. We will do VLSM in the future
> (its one of the Big Four Requests).
>
BIG BIG BIG request!
> Revision B of the Configuration Guide for PortMaster Products (now over 300
> pages but not out yet) will discuss netmasks and routing on PortMasters
> in all the detail you can stand, and more.
>
Uh huh... :-)
Owen