When our Network was setup 3 years ago, the IP Address range we'd been
assigned by our local authority was more than sufficient - we had ~1000
IP's to play with, ( and only needed 300 or so.

Since then, we've added a LOT more kit, and by this time next year I'll
have run out of IP's.

I know that an easy fix would be to change the subnet mask and tweak
our DHCP server - But we have a second network on site, which uses a
similar address range and must remain invisible to the first.

How should I go about changing the IP's of my six Netware 6.5 servers?
Can I simply add an additional IP and subnet to each server, so that i
can phase in the changeover? If not, this is not a huge issue, as I
work in a school, and can afford downtime during holidays.

How do I go about making the changes?

Many Thanks