Vrrp - Allied Telesis SwitchBlade x908 Series Software Reference Manual

Routing Protocol Overview
PIM-SM
The AlliedWare Plus
multicast routing protocol module that uses the underlying unicast Routing Information Base
(RIB) to determine the best next-hop neighbor to reach the root of the multicast data
distribution tree, the Rendezvous Point (RP), or the source. It builds unidirectional-shared trees
per group, and optionally creates shortest-path trees per source.

VRRP

Mission-critical applications running on fault-tolerant networking equipment, such as routers
and switches, require redundancy and high availability. This section provides an architectural
overview of Virtual Router Redundancy Protocol (VRRP) implementation in the AlliedWare
Plus
Typically, end hosts are connected to the enterprise network through a single router (first-hop
router) that is in the same Local Area Network (LAN) segment. The most popular method of
configuration is for the end hosts to statically configure this router as their default gateway. This
minimizes configuration and processing overhead. The main problem with this configuration
method is that it produces a single point of failure if the enterprise network's first-hop router
fails.
VRRP attempts to solve this problem by introducing the concept of a virtual router, composed
of two or more VRRP routers on the same subnet. The concept of a virtual IP address is also
introduced, which is the address that end hosts configure as their default gateway. Only one of
the routers (called the Master) forwards packets on behalf of this IP address. In the event that
the Master fails, one of the other routers (Backups) assumes forwarding responsibility for it.
28.4
TM
Protocol Independent Multicast–Sparse Mode (PIM-SM) module is a
TM
OS.
Software Reference for SwitchBlade® x908, x900 and x600 Series Switches
TM
AlliedWare Plus Operating System - Software Version 5.3.1 C613-50007-01 REV B