[c-nsp] 7940 VLAN's

[lists at hojmark.org]

> Right thats one option.  Many options are RFC defined, and then
> there is also Vendor Specific options.  And some vendors do let
> you specify voice vlan via a dhcp option.  However, I am not 
> sure if Cisco's do.

AFAIK that's not supported.

Also, if they *did* send the VLAN number as a DHCP option, the phone would
boot and get an address in the data VLAN, then run DHCP again in the voice
VLAN and get another address in there.

Of course it wouldn't need to actually be active in both VLANs at the same
time, but it would use up addresses in the data VLAN DHCP scope, which could
be a pain, depending on the lease time and the size of the scope.

I guess that's one reason why instead they chose to signal the voice VLAN
via CDP, at least for the Skinny phone firmware.

-A