Polycom VLAN Defaults Firmware 5.8+
When the DHCP VLAN Discovery is set to Fixed, the phone will examine DHCP options 128,144, 157 and 191 (in that order) for a valid DVD string. When set to Custom, a value set in the VLAN ID Option will be examined for a valid DVD string. By default the DHCP VLAN Discovery option is set to Fixed, and displays DHCP VLAN Option 129. This does not mean the phone will only work on DHCP Option 129, the phone will still examine for Options 128, 144, 157, and 191.
Recommendation and Advisory
- For VLAN Discovery to function, it is required that CDP and LLDP are disabled on the switch.
- 8x8's recommendation is to use CDP and LLDP which is enabled by default for assigning VLANs to Polycom phones
- The VLAN ID is not set by default, and the DHCP VLAN Discovery is set to Fixed. The DHCP VLAN Option is set to 129, which is ignored by default.
Using methods for assigning VLANs to Polycom devices that are outside the default settings from Polycom will require manually modifying each device. For this reason 8x8 recommends using the default settings of CDP/LLDP or DVD (VLAN Discovery in the DHCP menu is set to Fixed, the phone examines for DHCP options 128, 144, 157, and 191 in that order for a valid Digital Versatile Disk DHCP VLAN Discovery string) for assigning the VLAN.