GCP IPv6 route support with nextHopInstance

FortiOS 7.4.4 and later versions support IPv6 high availability (HA) routes. GCP IPv6 routes support the nextHopInstance attribute. When an HA active-passive failover occurs, the FortiGate-VM uses the nextHopInstance attribute to update IPv6 routes.

HA configuration on IPv6 is the same as IPv4 except for the key points that this document outlines in the following section.

The following lists prerequisites for using IPv6 HA routes:

• The following GCP elements must already exist. Otherwise, you must create them:
  • IPv6 networks
  • IPv6 route table for the internal subnet
• Two GCP FortiGate-VMs running FortiOS 7.4.4 installed and licensed with HA configuration working and in-sync

To add an IPv6 route to the SDN connector on both FortiGate HA nodes:

In the following example, "route-internal" is a nextHopIP route that is the IPv4 route on GCP routing table. "route-internal-ipv6" is a nextHopInstance route that is the IPv6 route on GCP routing table.

config system sdn-connector

edit "gcp_conn"

config route

edit "route-internal"

next

edit "route-internal-ipv6"

next

end

end

The FortiGate-VM detects the route table type and decides which route table attribute to use upon failover.