組網拓撲：

故障描述：
兩台出口路由器(qì)分别配置OSPF動态路由協議與運營商互連，內(nèi)網用戶網關配置VRRP并與上(shàng)行(xíng)鏈路配置NQA聯動，當路由器(qì)到運營商鏈路不通(tōng)時(shí)，實現VRRP切換。上(shàng)行(xíng)用網線鏈接運營商的光纖收發器(qì)，光纖收發器(qì)出來(lái)的是尾纖。當路由器(qì)的上(shàng)行(xíng)網線斷開(kāi)時(shí)，線路切換正常。但(dàn)是當光纖收發器(qì)的上(shàng)行(xíng)端開(kāi)，線路就不能切換。
相關配置：
RT01：
interface GigabitEthernet0/0/0
description TO_yidong
ip address 172.148.68.6 255.255.255.252
ospf network-type p2p
#
interface GigabitEthernet0/0/1.10
dot1q termination vid 10
ip address 168.148.68.34 255.255.255.224
vrrp vrid 10 virtual-ip 168.148.68.33
vrrp vrid 10 priority 120
vrrp vrid 10 track nqa admin test reduced 30    
#
interface GigabitEthernet0/0/1.20
dot1q termination vid 20
ip address 168.148.196.34 255.255.255.224
vrrp vrid 20 virtual-ip 168.148.196.33
#
nqa test-instance admin test
test-type icmp
destination-address ipv4 172.148.68.5
source-address ipv4 172.148.68.6
frequency 8
start now#

RT02：
#
interface GigabitEthernet0/0/0
description TO_dianxin
ip address 172.148.196.6 255.255.255.252
ospf network-type p2p
#
interface GigabitEthernet0/0/1.10
dot1q termination vid 10
ip address 168.148.68.35 255.255.255.224
vrrp vrid 10 virtual-ip 168.148.68.33   
#
interface GigabitEthernet0/0/1.20
dot1q termination vid 20
ip address 168.148.196.35 255.255.255.224
vrrp vrid 20 virtual-ip 168.148.196.33
vrrp vrid 20 priority 120
vrrp vrid 20 track nqa admin test reduced 30
#
nqa test-instance admin test
test-type icmp
destination-address ipv4 172.148.196.5
source-address ipv4 172.148.196.6
frequency 8
start now
#

1、斷開(kāi)中間(jiān)傳輸鏈路後，使用命令display vrrp查詢兩邊VRRP主備無變化，主備優先級與NQA聯動未生(shēng)效。
2、使用命令display nqa results test-instance admin test查詢設備NQA測試統計(jì)信息，發現鏈路斷開(kāi)後NQA測試例一直為running狀态，測試結果為no result。
3、檢查設備配置，發現測試例frequency參數(shù)配置不合理(lǐ)，NQA無正确結果返回，導緻VRRP切換不生(shēng)效。修改NQA測試例frequency參數(shù)值為15，啓動NQA測試。重新斷開(kāi)中間(jiān)鏈路測試，VRRP主備切換成功。

NQA配置ICMP測試例frequency參數(shù)配置不合理(lǐ)導緻VRRP與NQA聯動不生(shēng)效。

在ICMP、SNMP、TCP或UDP類型的測試例中，frequency取值必須大(dà)于interval和(hé)probe-count取值的乘積。AR G3系列路由器(qì)默認配置NQA測試例的發送ICMP報文的時(shí)間(jiān)間(jiān)隔interval值為4，發送探針數(shù)目probe-count值為3。如frequency值配置不合理(lǐ)将會(huì)導緻NQA測試例無正确結果返回。