Associating A Vrrp Backup Group With An Nqa Test Instance - Huawei AR2200-S Series Configuration Manual

Huawei AR2200-S Series Enterprise Routers
Configuration Guide - Reliability
A VRRP backup group can track a maximum of eight BFD sessions and eight interfaces
simultaneously.
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2.9.3 Associating a VRRP Backup Group with an NQA Test Instance

After being associated with a Network Quality Analysis (NQA) test instance, a VRRP backup
group can track the status of the NQA test instance. If the NQA test instance detects that the
monitored IP address becomes unreachable, it notifies the VRRP backup group of a status
change, triggering a rapid master/backup VRRP switchover.
Context
A VRRP-enabled AR2200-S can track a local forwarding interface connected to a network, but
not an interface along a network-side link connected to the local forwarding interface. If the
interface along the network-side link goes Down, the VRRP backup group cannot detect the
fault but continues to send packets along the link, causing user traffic loss.
To monitor the connectivity of the interface on the network-side link, an NQA ICMP test instance
can be configured on the NQA-supported AR2200-S and send test packets to the IP address.
The VRRP backup group can be associated with the NQA ICMP test instance. The NQA ICMP
test instance reports the link status to the VRRP backup group. This mechanism enables the
VRRP backup group to monitor the link connecting the master AR2200-S to the external
network. If the link fails, hosts on a LAN cannot access an external network through the master
router. NQA detects this fault and notifies VRRP of the fault. The VRRP backup group lowers
the master router's priority by a configured value. The backup router with the highest priority
will become the new master router and take over traffic. The process ensures that the
communication between the hosts and the external network is not interrupted. After the link
recovers, NQA detects the status change and instructs the VRRP backup group to restore the
priority of the previous master router.
Figure 2-2
helps the VRRP backup group monitor the link between the master router and a network.
Figure 2-2 Networking diagram for association between VRRP and an NQA test instance
Switch
HostA
Issue 01 (2012-01-06)
shows a network where a VRRP backup group tracks an NQA test instance. NQA
Master
RouterA
NQA agent
RouterB
Backup
VRRP Backup Group
Virtual IP Address:10.1.1.10
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RouterC
20.1.1.1/24
Internet
RouterD
2 VRRP Configuration
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