7940 SIP - disable CDP

Unanswered Question
May 25th, 2010

Hi All,

I have a Cisco 7940 loaded with the SIP image, everything works great (with a remote SIP proxy) except one thing.

I've connected this phone to an existing Cisco Catalyst configured with a dedicated voice vlan where other IP phones are connected (in SCCP to the internal CUCM). This phone is not authorized on the voice vlan and therefore he never gets any ip address from the DHCP server. When I plug it, its built-in ethernet switch gets automatically configured by the Catalyst and hence he's configured inside the voice vlan where he's blocked.

I would like to connect this phone to the data vlan, I guess the phone gets its ethernet ports configuration from the CDP messages sent by the Catalyst.

Do you know how I could manually tell its built-in switch to discard the VLAN configuration?

Thanks a lot for your help,


PS: I can not change the Catalyst configuration.

I have this problem too.
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gogasca Fri, 05/28/2010 - 13:42

You may need to connect the phone first to CUCM to a different switch OR contact the Switch admin and change the CUCM config

Cisco Discovery Protocol (CDP): Switch PortRequired Field to disable

then connect it to the Catalyst


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