Voice VLAN - simple question/no answer yet

Unanswered Question
Apr 5th, 2007
User Badges:


Im after an answer to this for some time now, couting on some expert feedback.

If you set up a voice vlan and access vlan on a cisco sitch port, but you have an ip phone which does not do CDP but can do 802.1x.

Hence I set up the VLAN and CoS on the ip phone to match the voice vlan on the switch and connect the ip phone the switchport set as above. (not trunk port)

Will the cisco switch smart enough to say:"The device is sending data on same vlan as the voice vlan, so it must be voice traffic. So I will let it trough"?

2. Second part of my question relates to a PC connected to port2 of IP phone. I guess the sitch will have no problem with that.

Any views?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
sunnyverghese Thu, 04/05/2007 - 03:09
User Badges:


i didnt get it exactly what you are looking for .Eventhough i will provide the configuration for the switch

interface GigabitEthernet1/0/9

switchport access vlan 125

switchport mode dynamic desirable

switchport voice vlan 126

storm-control broadcast level 0.05

spanning-tree portfast

the ip phone will take the voice vlan 126 and the computer will take the data vlan 125

i am not sure will it sort your problem.

if not kindly reply back

kindly do the ratings

rsabapathee Thu, 04/05/2007 - 04:57
User Badges:

the key here is that:

1) the ip phone does not do CDP

2) i dont want to configure switch port as trunk

paolo bevilacqua Thu, 04/05/2007 - 05:25
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

Now i'm not 100% sure, but suppose that switch in 'access mode + voice vlan' does not open up voice vlan unless sees CDP, you must use trunk.

rsabapathee Thu, 04/05/2007 - 05:38
User Badges:


so if an ip phone does not support CDP, only way to do it is set switch as trunk???


This Discussion