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8x8 Support

Poly Devices VLAN Overview and Recommendations


Poly VLAN Defaults for Firmware 5.8+

Poly VVX IP Phones natively will seek CDP and LLDP on boot.  Please refer Poly Knowledge Base ARTICLE ID:000040531 linked Here.

Please review the list of 8x8 currently supported Poly Firmware Here

Recommendation and Advisory

The following is based on the Poly Administration guide 5.9.0 under “Virtual Local Area Network (VLAN) ID Assignment Using DHCP".


If a VLAN tag is assigned by CDP or LLDP, DHCP VLAN tags are ignored.

  • 8x8's recommendation is to use Poly's native CDP and or LLDP.
  • DHCP Discovery if used over CDP or LLDP, Both CDP and LLDP must be disabled at the Switch level.
  • There is no need to disable or modify Polys CDP or LLDP. If CDP and LLDP are disabled at the switch the Poly will boot successfully with DHCP Discovery.

Default Recommendations


When using a Voice Only VLAN (a Virtual LAN with only Hard Phones, and no computers on it), 8x8 recommends that you set the 8x8 GTMs, and as the Primary and Secondary DNS servers in the VLANs DHCP Scope. An alternate option is 8x8 can set the DNS of your hard phones to the GTMs. This ensures proper Geo Routing of your 8x8 traffic to the closest 8x8 data center for each location. 

8x8 UCasS Clients use the 8x8 GTMs directly (with a fall back of the local DNS); thus, no additional work is needed to ensure proper routing of the traffic for UCaaS Clients. 


8x8's recommendation for NTP is to allow the default NTP setting of through the firewall. If your internal security requirements do not allow for external NTP, our advice is to use Option 42 in your DHCP scope to override the NTP setting to an NTP server of your choice. Should you not have an internal NTP server, please use

Additional Information

Assigning VLANs to Poly devices that are outside the default settings from Poly will require manually modifying each device. For this reason, 8x8 recommends using CDP/LLDP the default settings as described above. If opting for DVD, (VLAN ID Discovery over DHCP) Poly natively examines for DHCP options 128, 144, 157, and 191 in that order for a valid Digital Versatile DVD Discovery string.

Warning on Using 8x8 GTM as DNS

8x8 GTM DNS wil not resolve public based FQDN as example for images hosted on websites with The Hosting URL should be IP based as