l
If the link between BRAS 1 and router A or between BARS 1 and router B fails, the link
bandwidth between BRAS 1 and the IP core network decreases. The NPEs, however, cannot
detect the link failure and keep sending packets to the IP core network through BRAS 1.
As a result, the other link between BRAS 1 and the IP core network may be overloaded.
l
If the links between BRAS 1 and router A and between BARS 1 and router B both fail,
only the links between BRAS 2 and the IP core network are available. The NPEs, however,
cannot detect the link failure and keep sending packets to the IP core network through
BRAS 1. As a result, the packets are discarded.
Figure 11-2
Route monitoring group
......
......
Router A
Router B
NPE 1
NPE 2
NPE m
BRAS 1
BRAS 2
IP Core
Primary path
Backup path
Network side
Access side
To address the packet drop issue, deploy a route monitoring group on each BRAS, and add
network-side routes of the BRAS to the route monitoring group. If the down-weight sum of the
route monitoring group reaches the switchover threshold of a service module that is associated
with the group, the RM module instructs the service module to perform a primary/backup access-
side link switchover. This mechanism prevents traffic overload and service interruptions.
Data Preparation
To configure a route monitoring group, you need the following data.
HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
11 Route Monitoring Group Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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