Technical Tip: FortiGuardDDNS redundancy scenarios

Scenario 1:

Topology:

FortiGate - WAN1 and WAN2 < - > ISP < - > Internet.

WAN interfaces are used for FortiGuard DDNS configuration:

config system ddns
    edit 1
        set ddns-server FortiGuardDDNS
        set addr-type ipv4
        set server-type ipv4
        set ddns-domain "test1.fortiddns.com"
        set use-public-ip disable
        set update-interval 0
        set monitor-interface "wan2" "wan1"
    next
end

When WAN1 is down, FortiGuard DDNS of WAN2 should respond:

For this scenario, the WAN1 interface must be in a down status:

Test1MX # diagnose hard deviceinfo nic wan1
========== Link Status ==========
Admin :down <----------------- Down.

Scenario 2:

Topology:

FortiGate - WAN1 and WAN2 < - > ISP < - > Link failure < - > Internet.

WAN1 and WAN2 interfaces are UP, but the Internet link of WAN1 has an issue.

WAN interface is UP, but the link has an issue reaching the Internet:

Test1MX # diagnose hard deviceinfo nic wan1
========== Link Status ==========
Admin :up <----------------- Up.

Currently, this FortiGuard DDNS redundancy scenario 2 does not support it.
Link monitor service will not work for FortiGuard DDNS failover.

The development team is working to have DDNS redundancy for scenario 2 working in future releases.