The term router in this document refers to both routers and Layer 3 switches.
The term interface in the VRRP feature refers to Layer 3 interfaces, including VLAN interfaces and route-
mode (or Layer 3) Ethernet ports. You can set an Ethernet port to operate in route mode by using the
port link-mode route command (see Layer 2—LAN Switching Configuration Guide).
Typically, as shown in
every host on a network segment. All packets destined to other network segments are sent over the
default route to the gateway, which then forwards the packets. However, when the gateway fails, all
hosts that use the gateway as the default next-hop router fail to communicate with external networks.
Figure 29 LAN networking
Configuring a default route for network hosts facilitates your configuration, but also requires high
performance stability of the device that acts as the gateway. Using more egress gateways is a common
way to improve system reliability, but it introduces the problem of routing among the egresses.
VRRP is designed to address this problem. VRRP adds a group of routers that can act as network
gateways to a VRRP group, which forms a virtual router. Routers in the VRRP group elect a master
through the VRRP election mechanism to act as a gateway, and hosts on a LAN only need to configure
the virtual router as their default network gateway.
VRRP is an error-tolerant protocol, which improves the network reliability and simplifies configurations on
hosts. On a multicast and broadcast LAN such as Ethernet, VRRP provides highly reliable default links
without configuration changes (such as dynamic routing protocols, route discovery protocols) when a
router fails, and prevent network interruption due to a single link failure.
VRRP works in standard protocol mode, and includes two versions: VRRPv2 and VRRPv3. The two
versions implement the same functions but apply to different networks: VRRPv2 is for IPv4 networks, and
VRRPv3 is for IPv6 networks. For more information, see
29, you can configure a default route with the gateway as the next hop for
"VRRP standard protocol