Reference Guide
Supported Releases 10.3.0E or later
Virtual router redundancy protocol
VRRP allows you to form virtual routers from groups of physical routers on your LAN. These virtual routing platforms — master and backup
pairs — provide redundancy in case of hardware failure. VRRP also allows you to easily congure a virtual router as the default gateway to
all your hosts and avoids the single point of failure of a physical router.
VRRP advantages in ease of administration and network throughput and reliability:
• Provides a virtual default routing platform
• Provides load balancing
• Supports multiple logical IP subnets on a single LAN segment
• Enables simple trac routing without the single point of failure of a static default route
• Avoids issues with dynamic routing and discovery protocols
• Takes over a failed default router:
• Within a few seconds
• With a minimum of VRRP trac
• Without any interaction from hosts
Conguration
VRRP species a master (active) router that owns the next hop IP and MAC address for end stations on a LAN. The master router is
chosen from the virtual routers by an election process and forwards packets sent to the next hop IP address. If the master router fails,
VRRP begins the election process to choose a new master router which continues routing trac.
VRRP packets are transmitted with the virtual router MAC address as the source MAC address. The virtual router MAC address associated
with a virtual router is in format: 00:00:5E:00:01:{VRID} for IPv4 and 00:00:5E:00:02:{VRID} for IPv6. The VRID is the virtual router
identier that allows up to 255 IPv4 VRRP routers and 255 IPv6 VRRP routers on a network. The rst four octets are unquenchable, the
last two octets are 01:{VRID} for IPv4 and 02:{VRID} for IPv6. The nal octet changes depending on the VRRP virtual router identier and
allows for up to 255 VRRP routers on a network.
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Layer 3