The common method to improve the system reliability is to deploy multiple egress gateways.
In addition, the problem of selecting routes among these gateways should be solved. The Virtual
Router Redundancy Protocol (VRRP) is a fault-tolerant protocol defined in RFC 3768. VRRP
solves the problem of route selection among egress gateways by separating the physical devices
from logical devices.
On Ethernet enabled with multicast or broadcast, VRRP offers logical gateways to ensure highly
available link. This solves the problem that services are interrupted because of a gateway
router failure, without changing the configuration of routing protocol.
1.3.4 BFD
As a unified detection mechanism on an entire network, Bidirectional Forwarding Detection
(BFD) can fast detect network faults, minimize the impact of device faults on services, and
improve availability of a network.
BFD is a set of entire-network applicable detection mechanisms. It is used to detect and monitor
the connectivity of a link or an IP route during forwarding packets. To improve the network
performance, a communication failure between adjacent systems must be detected quickly and
the standby channel must be created faster for communication recovery.
The BFD features are as follows:
l
Detecting channel failures between adjacent forwarding engines with light load in a short
time
l
Detecting any media and any protocol layer with single mechanism in real time and
supporting different detection time and costs
1.4 Networking of Reliability over an IP Network
This section describes FRR applicable scenarios and FRR solutions.
1.4.1 Failures on Intermediate Nodes or on the Link Between PEs -
LDP FRR/TE FRR
In LDP or TE FRR, when transmission devices exist between P devices, BFD or OAM can be
used to detect links that transmit traffic.
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
1 Reliability Overview
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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