Vrrp standard protocol mode, Introduction to vrrp group – H3C Technologies H3C SecPath F1000-E User Manual
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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 introduces the problem of routing among the egresses.
Virtual Router Redundancy Protocol (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 either of the following two modes:
•
Standard protocol mode: Includes two versions VRRPv2 and VRRPv3 based on RFCs. VRRPv2 is
based on IPv4, and VRRPv3 is based on IPv6. The two versions implement the same functions but
are applied in different network environments. For more information, see
.
•
Load balancing mode: Extends the standard protocol mode and realizes load balancing. For more
information, see
.
VRRP Standard Protocol Mode
Introduction to VRRP Group
VRRP combines a group of routers (including a master and multiple backups) on a LAN into a virtual
router called VRRP group.
A VRRP group features the following:
•
A virtual router has a virtual IP address. A host on the LAN only needs to know the IP address of the
virtual router and uses the IP address as the next hop of the default route.
•
Every host on the LAN communicates with external networks through the virtual router.
•
Routers in the VRRP group elect a master that acts as the gateway according to their priorities. The
other routers function as the backups. When the master fails, to ensure that the hosts in the network
segment can uninterruptedly communicate with the external networks, the backups in the VRRP
group elect a new gateway to undertake the responsibility of the failed master.