PTP820 with Fortinet Switches

The PTP820 series can work with Fortinet switches, including the FortiGate firewall appliances.  However, a configuration change is necessary to allow them to form a tunnel across the PTP link. 

The FortiGate appliances create a tunnel between the master and remote ends for management traffic (including initial DHCP request).  In order to form the tunnel, the remote end searches for the master using LLDP.

In order for this process to work properly on the PTP820 radios, LLDP on the PTP820's needs to be disabled.  If LLDP support is enabled on the PTP820, the PTP820 radio responds to the LLDP neighbor request instead of forwarding it on.  Once LLDP is disabled on the PTP820, the request is able to traverse the link and the tunnel is setup properly.  This traffic is considered payload traffic and will be sent using the P2P/MP data service configured in the PTP820.  If using in-band management, it is recommended to set the C-VLAN as the management VID and not the Fortinet native VLAN of 4094.

LLDP is located under Ethernet>Protocols>LLDP>Advanced>Configuration>Port Configuration.  Modify the payload data interface and apply.  See screenshot