VRRP is a first hop redundancy protocol (FHRP). It provides gateway redundancy by enabling a pair of VRRP routers to coordinate and act as one gateway. If one VRRP router fails, the other router will detect its missing peer, and become the active gateway.
Although VRRP is traditionally an active/standby protocol, meaning only one VRRP router is forwarding at a time, when VRRP is used between VLT peers, it becomes active/active.
Even the backup VRRP router will forward packets for hosts and end devices. In this guide, VRRP version 3 is specified.
VRRP version 3 supports IPv6. It requires higher priority for preemption (with version 2, if both routers have the same priority, the router with the higher IP address will preempt), and uses millisecond timers for improved tunability.
