DHCP Option Filter not working as expected

[#1]

Want to provide a different TFTP server for a set of IP phones in the same subnet as different IP phones.

The IP phones provide their type in option 60 with the DHCP request, confirmed via packet capture.

Made ipv4 option filter.

Rules: vendor-class-identifier (60) Equals Polycom-VVX250
DHCP Options: Option dhcp4 tftp-server-name (66) Text different-servername

Attached it to the subnet used tcpdump on the B1 to check but nothing hapens due to the filter, the phone receives the default tftp server, not the one from the filter.

Any thoughts about this?

[#2]

With some trial and error figured out you can't use the option filter if you also set the DHCP option "normal".

After that it wasn't clear if the order in which filters are applied have an effect. Doesn't seem to be so you need to add filters that match all the devices else some might end up without the option you want to provide.

Interested if all this is documented somewhere, anyone know?