[c-nsp] reasons for giving new VLAN int a new IP

[Rogelio]

I've got a general question about VLANs that grew out of two separate 
VLAN implementations -- one on Cisco switches and another one on BelAir 
BA200 radios:

Do you have have to have to put an IP on that VLAN for traffic to flow? 
  Or only if you'd like to manage it from that VLAN?

Obviously, in general, an IP address (or even correct IP address) on a 
layer two device isn't necessary for traffic to flow through it, but I 
was thinking that there might be a possibility that some other "thing" 
(limitation in vendor implementations, practicality, feature set, 
controllers to work, etc) compelled putting an IP address on.

I've always added an IP on each VLAN on Cisco switches and recently 
started doing it on the BelAir BA200 quad radios out of habit.  (A 
coworker said that it wasn't required, and normally I'd test it out, but 
I'm not in a position  to easily test out this theory.)

Nothing earth shattering, but if anyone had any insight on the matter, 
I'd love to hear it.