Figure 1-5
Networking of the association between the direct route and PW status
AGG2
RSG2
AGG1
RSG1
RNC
NodeB
CSG
L2VPN
L3VPN
Link A
Link B
PW1
PW2
PW
AGG1 is used as the master device in the preceding figure. In normal cases, RSGs select routes
advertised by AGG1 and traffic travels along Link A. If AGG1 or the CSG-AGG1 link fails,
traffic is switched over to Link B. After AGG1 or the CSG-AGG1 link recovers, the L3VE
interface on AGG1 goes from Down to Up, and AGG1 immediately generates a direct route
destined for the CSG and advertises the route to RSGs. Downstream traffic is then switched over
to Link A. However, AGG1 has not learned the MAC addresses of the base stations yet and PW1
is standing by, so downstream traffic will be lost.
After you configure the association between the direct route and PW status, when the L3VE
interface on AGG1 goes from Down to Up, the cost of the direct route between the CSG and
AGG1 increases. In this case, RSGs do not preferentially select routes advertised by AGG1 and
downstream traffic still travels along Link B. After PW1 between the CSG and AGG1 becomes
the primary PW, the cost of the direct route between the CSG and AGG1 is restored to the default
value 0. Then, RSGs preferentially select routes advertised by AGG1 and downstream traffic is
switched over to Link A. At this time, AGG1 has learned the MAC addresses of the base stations,
downstream traffic loss will be reduced after the configuration.
Pre-configuration Tasks
Before configuring the association between the IPv4 direct route and PW status, complete the
following tasks:
l
Configuring link-layer protocol parameters and IP addresses for interfaces to ensure that
the link layer protocol of each interface is Up
Data Preparation
To configure the association between the IPv4 direct route and PW status, you need the following
data.
HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
1 IP Routing Basic Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
29