What are the heartbeat interface IP addresses on FortiGate HA deployments?
A quick reminder on some important IPs.
In order for FortiGate firewalls to communicate in a high-availability cluster, they need to know how to reach one another. Think of it like calling someone on the phone; If you don't know the other person's phone number, you don't have enough information to get communication started. So, how does this work for clustering? What are the HA addresses and how do they get chosen?
It's actually pretty simple.
During the initial HA setup/negotiation, the FortiGate Clustering Protocol (FGCP) looks at all of the serial numbers for the units in that cluster. It then sorts the serial numbers from highest to lowest and assigns a listening IP in the address range 169.254.0.0/26 . So for example:
169.254.0.1would be used by the FortiGate with the highest serial value.169.254.0.2would be used by the FortiGate with the next highest serial value.- Etc, etc, etc,
That's it! Nice and simple, right? For more information, check out these resources:
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