![Huawei Quidway NetEngine40E Скачать руководство пользователя страница 1178](http://html.mh-extra.com/html/huawei/quidway-netengine40e/quidway-netengine40e_configuration-manual-reliability_1694531178.webp)
11.5.1 Before You Start
Before configuring multi-device backup of BRAS user information, familiarize yourself with
the usage scenario, complete the pre-configuration tasks, and obtain the data required for the
configuration.
Usage Scenario
To improve the reliability of the network and shorten the interruption time, you need to configure
user information backup between master and slave devices. After the user is connected to the
master device, the master device backs up user information to the slave device and the slave
device generates user information and sends the forwarding table. When a fault occurs on the
network, user routes are controlled by master and slave devices so that the user traffic can reach
the slave device and is forwarded to the user. The user does not detect the fault during the fault
occurrence and can log in again without dialing.
Multi-device backup has become available for IPv4 users. As IPv6 develops, the remote backup
service is also needed for IPv6 access users to ensure reliability. To implement backup for
IPoEv6 and PPPoEv6 access users, as well as backup for both IPv4 and IPv6 users for smooth
upgrade, configure multi-device backup of BRAS user information on the devices that back up
each other.
NOTE
Note the following when configuring multi-device backup of BRAS user information on IPv6 networks:
l
The devices support ND/DHCPv6/ND+PD IPv6 hot backup for IPoE Layer 2 subscribers and support
IPoE dual-stack hot backup but do not support IPv6 static user backup.
l
For ND IPv6 hot backup, the deployment solution provides only the unshared prefix assignment
mode.
l
The devices support ND/DHCPv6/ND+PD IPv6 hot backup for PPPoE Layer 2 subscribers and
support PPPoE dual-stack hot backup.
l
IPv6 hot backup users and non-hot backup users can share an address pool. That is, IPv6 also supports
virtual backup.
l
IPv6 services' protection tunnels support only the MPLS LSP mode (6PE and 6VPE models).
l
IPv6 address pools do not support inter-chassis borrowing (the local RUI-slave address pool cannot
be used to assign an IP address to the master device).
l
IPv6 hot backup does not support address pool planning based on backup groups or links.
l
IPv6 hot backup does not support the mapping of RADIUS authorization address pool names to the
local device.
l
IPv6 multicast does not support hot backup.
l
IPv6 DAA does not support hot backup.
l
DS-Lite does not support hot backup.
l
IPv6 hot backup supports only local address pools.
l
The devices can connect to only the RADIUS server that uses the IPv4 address.
l
The devices can connect to the only web authentication server that uses the IPv4 address.
l
Dual-device hot backup does not interconnection with the COPS server.
l
The devices can use only VRRPv4.
l
IPv6 dual-device hot backup does not support the redirection tunnel mode.
l
IPv6 hot backup does not support VE interface access backup.
l
IPv6 hot backup supports SQ and CAR but does not support home HQoS.
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
11 Multi-node Backup Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
1161