Hi

I have seen lots of examples of ip phone ports set up like this..

interface FastEthernet0/4
switchport trunk encapsulation dot1q
switchport trunk native vlan 150
switchport mode trunk
switchport voice vlan 200
spanning-tree portfast
end

and this is kind of what I expected, whan having no experience in VOIP,
assumed that an ip phone would have to trunk if it was also handling a PC in
a different VLAN.

But when I read the "Configuring Voice VLAN" section of the IOS docco, I
don't recall it making references to this need, and in fact CDP is used to
handle the phone.

Thus is this perfectly valid?

interface FastEthernet0/4
switchport access vlan 150
switchport voice vlan 200
spanning-tree portfast
end

I occasionally get the phones obtaining a DHCP address from VLAN 150, rather
than 200. Would this be some breakdown in the CDP negotiation between
phone->switch?

Anybody seen this before?