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Voice VLAN DHCP option 66 & Option 150

Abhishek Sharma
Level 1
Level 1

I have a question...   I have environment that has a Voice VLAN already DHCP scope is configured with option 66 pointing to TFTP server e.g: and Avaya phone are running.  We need to put cisco phone on the same vlan.  So i configured DHCP scope with option 150 pointing to TFTP server e.g. on the same voice vlan.  Most of my cisco phones are working..  Couple of Cisco phone are picking OPTION 66 which points to wrong TFTP leading to registration error..  My question is can I force Cisco phones 7841, 7811 phone to always use option 150.  Please let me know

3 Replies 3


Is the DHCP scope created on some Cisco device or is it located on a server? If it is the first one, the option 150 can be configured under the DHCP pool.

Please check these links, it could be useful:


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Thanks for your response..  We have both options configured on CISCO CNR..  OPTION 150 is suppose to be for CISCO phone and option 66 is for Avaya.  The issue is Cisco is picking option 66. My Avaya is no issue as i guess it only supports option 66.

The best way would be creating a new vlan either cisco ipphone or avaya phone so that you can seperate TFTP IP addresses per vlan by using either option 66 or option 150.

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