I have a scenario whereby i need to change the option 150 for a whole load of IP phones. I changed the option 150 setting on the DHCP server and reset the phone from call manager; It didnt pick it up. I restarted it from call manager; it didnt pick it up. The only way i could get it to pickup the new option 150 was to physically **#** the phone or shut/no shut the switchport.
Is there a way to make them pick this up from a straight reset?
Not to my knowledge. The phone gets its DHCP options when it boots and when it renews the DHCP lease at halfway through the lease time. If you have the luxury of planning for this change, one option would be to reduce the DHCP lease time. The next time the phone renews its lease it will be for a short time and will be renewed at half of that time. So if you set the lease for 1 hour, it will renew at 30 minutes. When you make the option 150 change, each phone should have the right setting within 30 minutes.
