Physical Network Topology
As shown in the figure, two CE12800 devices form a stack system and serve as an outlet for the data center. CE12800A and CE12800 B provide two links to the CE12800 stacking system, one of which acts as the primary link and one serves as the standby link. To ensure that the traffic of the stack system can be quickly switched to the standby link when the uplink fault occurs on the primary link side of the STACK and the CE12800, you need to configure the NQA to detect the primary link side IP address and the associated static route function on the CE12800.
Figure 1-1 NQA detection and linkage static routing function fail
Fault Description
After the configuration is complete, the NQA function configured on the STACK does not take effect. The default route of the stack system is still directed to the active link side.
Configuration Files
#
nqa test-instance NQA NQA1
test-type icmp
destination-address ipv4 192.168.20.28
source-address ipv4 192.168.40.28
interval seconds 1
timeout 1
frequency 2
start now
#
ip route-static 0.0.0.0 0.0.0.0 10.1.11.28 preference 40 track nqa NQA NQA1
//master
ip route-static 0.0.0.0 0.0.0.0 10.1.12.28
Troubleshooting Procedure
Step 1 When the uplink of the primary link-side CE12800-A is faulty, check the routing table information of the CE12800 and find that the route of the active link is not switched. The NQA association static route does not take effect. You need to check the history of the NQA.Run the display nqa history command on the CE12800 to check the NQA running history. You can view the NQA running status. You need to check the NQA running result.
[~CE12800-1] display nqa history
T/H/P = Test ID/Hop ID/Probe ID
NQA entry(NQA, NQA1) history:
-----------------------------------------------------------------------------------------
Index T/H/P Response(ms) Status
Address Time
-----------------------------------------------------------------------------------------
1
300/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.530
2
301/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.535
3
302/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.534
4
303/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.537
5
304/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.528
6
305/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.528
7
306/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.531
8
307/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.531
9
308/1/1
1000 timeout 192.168.20.28 2015-10-28 19:43.532
Step 2 Run the display nqa results command on the CE12800 to check the NQA running result. The NQA probes in the current configuration are no result. The association between the NQA and the static route is unsuccessful.
[~CE12800-1] display nqa results
NQA entry(NQA, NQA1): test flag is active, test type is ICMP
1 . Test 351 result The test is finished
Send operation times:
1
Receive response times: 0
Completion: no
result
RTD over thresholds number: 0
Attempts number:
1
Drop operation number: 0
Disconnect operation number:
0 Operation timeout number: 1
System busy operation number:
0 Connection fail number: 0
Operation sequence errors number: 0 RTT Status
errors number: 0
Destination IP address: 192.168.20.28
Min/Max/Average completion time: 0/0/0
Sum/Square-Sum completion time: 0/0
Last response packet receiving time: 2015-10-28 19:43.0
Lost packet ratio: 100 %
2 . Test 352 result The test is finished
Send operation times:
1
Receive response times: 0
Completion: no
result
RTD over thresholds number: 0
Attempts number:
1
Drop operation number: 0
Disconnect operation number:
0 Operation timeout number: 1
System busy operation number: 0 Connection
fail number: 0
Operation sequence errors number: 0 RTT Status
errors number: 0
Destination IP address: 192.168.20.28
Min/Max/Average completion time: 0/0/0
Sum/Square-Sum completion time: 0/0
Last response packet receiving time: 2015-10-28 19:43.0
Lost packet ratio: 100 %
3 . Test 353 result The test is finished
Send operation times:
1
Receive response times: 0
Completion: no
result
RTD over thresholds number: 0
Attempts number:
1
Drop operation number: 0
Disconnect operation number:
0 Operation timeout number: 1
System busy operation number:
0 Connection fail number: 0
Operation sequence errors number: 0 RTT Status
errors number: 0
Destination IP address: 192.168.20.28
Min/Max/Average completion time: 0/0/0
Sum/Square-Sum completion time: 0/0
Last response packet receiving time: 2015-10-28 19:43.0
Lost packet ratio: 100 %
When the link between the NQA and the static route is detected in the NQA test instance, that is, when the Completion is fail, the device deletes the static route from the IP routing table. If the result of the Completion is no, the NQA test is in progress and the result is not obtained. Therefore, the NQA association static route function fails, and the device does not perform route switching.
Step 3 Check the NQA configuration of the CE12800. The interval at which the NQA test instance sends probe packets is 1 s. The time interval for the automatic test execution of the NQA test instance is 2 s. The timeout period for the NQA test instance. For 1s.
nqa test-instance NQA NQA1
test-type icmp
destination-address ipv4 192.168.20.28
source-address ipv4 192.168.40.28
interval seconds 1
timeout 1
frequency 2
start now
#
ip route-static 0.0.0.0 0.0.0.0 10.1.11.28 preference 40 track nqa NQA
NQA1//master
ip route-static 0.0.0.0 0.0.0.0
10.1.12.28
//backup
By default, the number of probe packets sent by an NQA probe is 3, and the packets to be detected all respond or do not respond within the timeout time. The NQA detection result is obtained. The detection result is always no result. The reason is that in this example, the time for completing an NQA probe is interval*probe-count=1*3=3 seconds, and the interval for automatically performing the test in the NQA test instance is 2 seconds, that is, when the NQA detects 2 seconds. The next probe is automatically executed, and the test is not completed yet, so the test result is no result.
Step 4 According to the above, the reason why the NQA linkage static routing function fails is that the interval for automatically performing the test in the NQA test instance is unreasonable.
Step 5 After the parameters of the probe period are adjusted, the static route entries can be linked and tracked normally.
Root Cause
The reason why the NQA linkage static route function fails is that the interval for automatically performing the test in the NQA test instance is unreasonable.
