I'm having a very hard time getting a Cisco 7960 working with my 2820n.

I have set the following:


> srv dhcp custom_option ?
Usage:
-e: enable/disable custom option feature, 1:enable, 0:disable
-t: custom option type, 1:one custom option with 64B data, 0:two options,each with 32B data
-o: option 1 code
-p: option 2 code
-q: option 64B code
-l: option 1 data
-m: option 2 data
-n: option 64B data
-h: display usage
-v: show the current settings
-f: clear all the settings

> srv dhcp custom_option -f
> srv dhcp custom_option -e 1
> srv dhcp custom_option -t 0
> srv dhcp custom_option -o 150 -l 192.168.200.1
> srv dhcp custom_option -p 66 -m 192.168.200.1
> srv dhcp custom_option -v

Custom DHCP option settings:

---

enable this feature: Yes
option type: two options, each with 32B data, please see (a),(b) below


(a) Custom DHCP option 1 [status: ACTIVE]:
code: 150
len: 13
data: 192.168.200.1

(b) Custom DHCP option 2 [status: ACTIVE]:
code: 66
len: 13
data: 192.168.200.1


Also I have set the TFTP server for good measure:

> srv dhcp tftp ?
%% srv dhcp tftp <TFTP server name>
% Now: 192.168.200.1


But the phone refuses to take the TFTP server.

Why?

I have the same issue with a 7940 ,option 150 will pass the tftp but is not the correct one.
Tftp I see on the phone is my gw ,in a couple of occasions he received an external ip address! (ok maybe is my fault need to check fw)
Did you resolved your problem?

No, and DrayTek was unwilling to assist either. It's clearly a bug.