Description:
NQA binded with two equal cost routes doesn’t take effect.
NQA is configured to probe the connection of the link. Users cannot get to the internet after the interface which connects to ISP1 is shutdown.
Corresponding configuration:
ip route-static 0.0.0.0 0.0.0.0 1.x.x.254 track nqa ISP2 ISP2_GW
ip route-static 0.0.0.0 0.0.0.0 2.x.x.254 track nqa IPS1 ISP1_GW
nqa test-instance ISP1 ISP1_GW
test-type icmp
destination-address ipv4 2.x.x.254
frequency 20
start now
nqa test-instance ISP2 ISP2_GW
test-type icmp
destination-address ipv4 1.x.x.254
frequency 20
start now
Process
From the testing result of the NQA, lost packet ratio is 0, which means the reasult is success and the link state is fine,
<Huawei> display nqa results test-instance yidong yidongwangguan
NQA entry(admin, icmp) :testflag is inactive ,testtype is icmp
1 . Test 1 result The test is finished
Send operation times: 3 Receive response times: 3
Completion:success RTD OverThresholds number: 0
Attempts number:1 Drop operation number:0
Disconnect operation number:0 Operation timeout number:0
System busy operation number:0 Connection fail number:0
Operation sequence errors number:0 RTT Status errors number:0
Destination ip address:2.x.x.254
Min/Max/Average Completion Time: 2/2/2
Sum/Square-Sum Completion Time: 6/12
Last Good Probe Time: 2015-09-18 09:09.1
Lost packet ratio: 0 %
The route towards to the ISP1 exists.
<AR>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 6 Routes : 6
Destination/Mask Proto Pre Cost Flags NextHop Interface
0.0.0.0/0 Static 60 0 D 2.x.x.254 GigabitEthernet0/0/1 //ISP1
Static 60 0 D 1.x.x.254 GigabitEthernet0/0/2 //ISP2
Root cause
G0/0/2 is up though the interface G0/0/1 is shutdown. The NQA testing result is normal because of the probe packet is sent from interface G0/0/2, which doesn’t deactivate the ISP1 route.
Solution
Assign the source IP address of the probe packets.
nqa test-instance yidong yidongwangguan
test-type icmp
destination-address ipv4 2.x.x.254
source-address ipv4 2.x.x.1
frequency 20
start now
nqa test-instance liantong liantongwangguan
test-type icmp
destination-address ipv4 1.x.x.254
source-address ipv4 1.x.x.1
frequency 20
start now
