DHCP Option 150 or 66

[deeshar]

Hello,

Could anyone please inform me the significance of the DHCP option 150 for Cisco IP phone. We would be migrating from Avaya to Cisco very shortly. Do we need DHCP option configured, if our DNS server has the information of the Tftp server or know about the location of Bootp.

Thanks,

Deepak

[mchandak · Accepted solution]

With DHCP, you will need either option 150 or 66 configured. When the Phone boots and gets information from the DHCP Server the following order if followed to connect to the TFTP Server and download the configuration.

1) Hardcoded TFTP Address

2) DNS lookup of CiscoCM1

3) Option 150

4) DHCP si_addr field

5) DHCP sname field

6) Option 66