发布时间: 2019-07-19 | 浏览次数: 909 | 下载次数: 9 | 作者: lxl@huawei | 文档编号： EKB1000327338
故障:
ISP1的链路发生故障时VRRP状态没有切换,R1仍为Master设备,导致用户无法正常访问总部。
1、分别在R1和R2上通过命令display vrrp brief查看VRRP状态:
<R1>dis vrrp brief
Total:2 Master:2 Backup:0 Non-active:0
VRID State Interface Type Virtual IP
----------------------------------------------------------------
10 Master GE0/0/0.10 Normal 10.10.10.3
20 Master GE0/0/0.20 Normal 20.20.20.3
<R2>dis vrrp brief
Total:2 Master:0 Backup:2 Non-active:0
VRID State Interface Type Virtual IP
----------------------------------------------------------------
10 Backup GE0/0/0.10 Normal 10.10.10.3
20 Backup GE0/0/0.20 Normal 20.20.20.3
可以看到VRRP的Master状态没有切换到R2上。
2、分别在R1和R2上通过命令display vrrp statistics查看VRRP报文的收发情况:
<R1>display vrrp statistics
GigabitEthernet0/0/0.10 | Virtual Router 10
Transited to master : 1
Transited to backup : 1
Transited to initialize : 0
Received advertisements : 4
Sent advertisements : 5413
Advertisement interval errors : 0
Failed to authentication check : 0
GigabitEthernet0/0/0.20 | Virtual Router 20
Transited to master : 1
Transited to backup : 1
Transited to initialize : 0
Received advertisements : 4
Sent advertisements : 5416
Advertisement interval errors : 0
Failed to authentication check : 0
--------------------------------------------------------------------
3、在R1上通过命令display nqa results查看NQA的运行监测情况:
<R1>display nqa results
NQA entry(ipcheck, 1) :testflag is active ,testtype is icmp
1 . Test 316 result The test is finished
Send operation times: 3 Receive response times: 0
Completion:failed RTD OverThresholds number: 0
Attempts number:1 Drop operation number:3
Destination ip address:100.100.100.2
Min/Max/Average Completion Time: 0/0/0
Sum/Square-Sum Completion Time: 0/0
Last Good Probe Time: 0000-00-00 00:00:00.0
Lost packet ratio: 100 %
2 . Test 317 result The test is finished
Send operation times: 3 Receive response times: 0
Completion:failed RTD OverThresholds number: 0
Attempts number:1 Drop operation number:3
Destination ip address:100.100.100.2
Min/Max/Average Completion Time: 0/0/0
Sum/Square-Sum Completion Time: 0/0
Last Good Probe Time: 0000-00-00 00:00:00.0
Lost packet ratio: 100 %
通过以上信息可以得知NQA测试实例运行正常,并已成功检测出上联链路发生了故障。要想使VRRP与NQA联动就必须在VRRP备份组中配置VRRP监视NQA测试实例的功能。所以接下来检查VRRP备份组中是否启用了该功能。
4、在R1上通过命令display current-configuration interface g0/0/0.10和display current-configuration interface g0/0/0.20查看两个VRRP备份组的配置情况:
<R1>display current-configuration interface g0/0/0.10
[V200R003C00]
#
interface GigabitEthernet0/0/0.10
description YeWu1
dot1q termination vid 10
ip address 10.10.10.1 255.255.255.0
vrrp vrid 10 virtual-ip 10.10.10.3
vrrp vrid 10 priority 120
vrrp vrid 10 preempt-mode timer delay 30
vrrp vrid 10 track nqa ipcheck 1
#
return
<R1>display current-configuration interface g0/0/0.20
[V200R003C00]
#
interface GigabitEthernet0/0/0.20
description YwWu2
dot1q termination vid 20
ip address 20.20.20.1 255.255.255.0
vrrp vrid 20 virtual-ip 20.20.20.3
vrrp vrid 20 priority 120
vrrp vrid 20 preempt-mode timer delay 30
vrrp vrid 20 track nqa ipcheck 1
在配置VRRP与NQA联动时,只是简单的开启了VRRP监视NQA测试实例的功能,并未指定具体的动作。缺省情况下当被监视的NQA测试实例变为Failed时,优先级的数值降低10,当前Master的配置优先级为120，降低10后仍高于Backup的优先级,所以VRRP状态无法正常切换。
针对以上情况在VRRP备份组中配置VRRP监视NQA测试实例功能时指定将VRRP优先级降低30。
在实际组网中单独使用VRRP往往无法保证在网络主链路发生故障时及时有效的将用户数据流切换到备份链路上,因此往往需要配合使用NQA、BFD等技术。在两种技术配合使用时除了要保证这两种技术本身配置正确外,还需注意两种技术的联动功能要配置准确无误。
