Active active cluster STP issues
I have 2 Fortigate 200F firewalls configured in an active/active cluster. Fail over between the firewalls seems to work fine but when I reboot one firewall the WAN port seems to become disabled. When I physically check the firewall I can see no lights on the port. If I physically disconnect and reconnect the port it will become active again.
We have 2 WAN cables which are connected to a pair of Dell switches which are stacked. Each firewall is connected to one switch.
When I view the switch logs I can see
"Link Down: Gi1/0/10
Link on Gi1/0/10 is failed
Gi1/0/10 is transitioned from Forwarding state to Blocking state in instance 0"
On the firewall I have configured port 12 as WAN
"FortiGate-200F-HA2 # show system interface port12
config system interface
edit "port12"
set vdom "root"
set ip x.x.x.x 255.255.255.192
set allowaccess ping https ssh http
set type physical
set lldp-reception enable
set role wan
set snmp-index 21
next
end"
Fortigate HA config
"FortiGate-200F-HA2 # show system ha
config system ha
set group-name "Carlow"
set mode a-a
set password ENC bcn2WjZogIhmGEQ6Erw0RhDrwBAZLZzQQvglVS00W7iNcVhb4SL21RyQpU7YEoIbpHJdg1lVzzUaB5HwcefjhvNy1VlBHpToznms3A3yTv6or6339ow+C1l3EDCVrplkfAiOx+qpMBvIpWRLQ=
set hbdev "ha" 0
set session-pickup enable
set override disable
set priority 140
set monitor "port12"
end"
Any advice on why this is happening would be much appreciated.