ip phone is getting data vlan DHCP address

[yeopaul]

Hi,

I have a cat 4006 trunk(dot1q) to a cat 3524. my ip phones attached to the cat 4006 is able to get the correct DHCP address. however, those on the cat 3524 is getting the DATA vlan DHCP address. My DHCP server is located on a Xylan switch, and the Xylan switch is using a cross cable to connect to the cat 4006.

ie.

XYLAN =cross=>Cat 4006 <=trunk= Cat 3524

| | |

DHCP phone--pc phone---pc

Could anyone advise me on the cause?

Thank you,

[mimckee]

Make sure the 3524 port is configured as follows for the phones.

switchport trunk encap dot1q

switchport trunk native vlan x (x is the data vlan)

switchport mode trunk

switchport voice vlan x (x is the voice vlan)

spanning-tree portfast.

Thank you,

-Mckee

[Vance Krier]

I've seen this multiple times where the DHCP server is plugged into a port that configured as a trunk with a voice-vlan... Changing back to mode access fixes it... Not sure what the underlying problem is, just know the quick fix..

Good luck,

Vance