Okay, I know all the smart kids out there are screaming, "But why
aren't you using NAT?" The short answer is *time* - or the lack
thereof. The HP WESMs (Wireless Edge Services Modules) do have NAT
support built-in. We could also use an external firewall placed in
front of the WESMs to perform NAT - or rather PAT since we really want
all the wireless users to shared a small pool of public IPs. We also
realize that, as the number of simultaneous wireless users grows
extremely large (say more than 16,000) and as our overall pool of
unused IP blocks dwindles, we will absolutely need to consider NAT on
wireless in order to conserve public IPv4 addresses.

HOWEVER ! We also need to deploy a few thousand APs in the next 2-3
months *AND* roll-out WPA2 Enterprise *AND* roll-out a new guest
access portal. Oh, and we have this other little project to
completely overhaul the core of the network and deploy MPLS VPNs
before August (I'll dive into that project in future posts). SO,
since we have an unused /16 block at our disposal, we think that's the
best course of action. We won't allow incoming TCP connection (no
wirelessly connected servers) and wireless clients are transient by
nature, so switching to NAT later on should be fairly painless - well,
for users at least :)