FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
This article describes how to use FortiOS CLI commands to control the number of ARP packets sent and their interval by the primary unit after a failover.
Scope
FortiGate.
Solution
It is possible to use the following command to set the number of gratuitous ARP packets that are sent after a failover.
Command syntax.
config system ha set gratuitous-arps <enable / disable ; default enable>
set arps <1 to 60; default 5>
set arps-interval <1 to 20; default 8>
end
Gratuitous ARP (GARP) packets are sent when a cluster unit becomes a primary unit.
The gratuitous ARP packets configure connected networks to associate the cluster virtual MAC address with the cluster IP address.
gratuitous-arps: Enables sending of gratuitous ARP packets. If link-failed-signal is enabled, GARP needs to be disabled.
arps -> Set the number of gratuitous ARP packets sent by the new primary unit after HA failover. Lower it to reduce traffic. Keep it higher to reduce failover time.
arps-interval -> Time between gratuitous ARPs. Lower the interval to reduce failover time. Keep it higher to reduce traffic.
