RuggedCom RuggedRouter RX1000 - Manual (Page 166)

RuggedRouter  User Guide
The router issues a set of gratuitous ARPs when moving between master and backup
state. These unsolicited ARPs teach the hosts and switches in the network of the
current MAC address and port associated with the VRIP. The router will issue a
second set of ARPs after the time specified by the Gratuitous ARP delay.
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