Hello: We currently operate our network with a subnet mask
of 255.255.255.0. However, I want to change the mask to
255.255.0.0 so I can access more ip addresses per subnet (we
run 10.1.1.0, 10.2.1.0 and 10.3.1.0, the last two across
wans).

What is the best why to do this? Change the servers first,
or network gear first? Or should I change client settings
first and servers/network gear last? What gotchas will I
come across?

Thanks, Chris.