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Frequent flapping of OSPF neighbor on S9706 Switch

Publication Date:  2014-10-21 Views:  126 Downloads:  0
Issue Description
We are observing frequent Flapping of OSPF neighbor on S9706 Switch. 
We have verified that there is no media related issue and also the link is underutilized with not much traffic on it.  

The Topology
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The Configuration
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interface LoopBack0
ip address 202.163.100.254 255.255.255.255

ospf 10 router-id 202.163.100.254
import-route direct route-policy export-direct2ospf
import-route static route-policy export-static2ospf
silent-interface LoopBack0
area 0.0.0.0
  network 202.163.100.0 0.0.0.31 description *** Core Devices ***
  network 202.163.100.40 0.0.0.3 description *** CSS-ASR9010 ***
  network 202.163.100.254 0.0.0.0 description *** Loopback of CSS ***





Alarm Information
Oct 18 2014 19:46:18-03:00 S9700-CSS %%01OSPF/4/NBR_CHANGE_E(l)[9]:Neighbor changes event: neighbor status changed. (ProcessId=10, NeighborAddress=202.163.100.2, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full)
Oct 18 2014 19:46:15-03:00 S9700-CSS %%01OSPF/4/NBR_CHANGE_E(l)[10]:Neighbor changes event: neighbor status changed. (ProcessId=10, NeighborAddress=202.163.100.2, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading)
Oct 18 2014 19:46:09-03:00 S9700-CSS %%01SECE/4/PORT_ATTACK_OCCUR(l)[11]:Auto port-defend started.(SourceAttackInterface=GigabitEthernet2/6/0/12, AttackProtocol=ICMP)
Oct 18 2014 19:46:04-03:00 S9700-CSS %%01OSPF/4/NBR_CHANGE_E(l)[12]:Neighbor changes event: neighbor status changed. (ProcessId=10, NeighborAddress=202.163.100.2, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange)
Oct 18 2014 19:46:04-03:00 S9700-CSS %%01OSPF/4/NBR_CHANGE_E(l)[13]:Neighbor changes event: neighbor status changed. (ProcessId=10, NeighborAddress=202.163.100.2, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=ExStart)
Oct 18 2014 19:44:59-03:00 S9700-CSS %%01OSPF/4/NBR_CHANGE_E(l)[14]:Neighbor changes event: neighbor status changed. (ProcessId=10, NeighborAddress=202.163.100.2, NeighborEvent=1-Way, NeighborPreviousState=Full, NeighborCurrentState=Init)
Oct 18 2014 19:44:59-03:00 S9700-CSS %%01OSPF/3/NBR_DOWN_REASON(l)[15]:Neighbor state leaves full or changed to Down. (ProcessId=10, NeighborRouterId=202.163.97.250, NeighborAreaId=0, NeighborInterface=Vlanif6,NeighborDownImmediate reason=Neighbor Down Due to 1-Wayhello Received, NeighborDownPrimeReason=1-Wayhello Received, NeighborChangeTime=2014-10-18 19:44:59-03:00)
Oct 18 2014 19:44:59-03:00 S9700-CSS %%01INFO/4/SUPPRESS_LOG(l)[16]:Last message repeated 1 times.(InfoID=1082200067, ModuleName=SNM
Handling Process
I found the reason of ospf down is [1-Wayhello Received]

Oct 20 2014 05:22:43-03:00 S9700-CSS %%01OSPF/3/NBR_DOWN_REASON(l)[216]:Neighbor state leaves full or changed to Down. (ProcessId=10, NeighborRouterId=202.163.97.250, NeighborAreaId=0, NeighborInterface=Vlanif6,NeighborDownImmediate reason=Neighbor Down Due to 1-Wayhello Received, NeighborDownPrimeReason=1-Wayhello Received, NeighborChangeTime=2014-10-20 05:22:43-03:00)

Usually, There are two probability that peer device will send 1-Wayhello packet
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1. Link is unstable between OSPF peers --->  I didn’t find ports up/down in the logs
2. illegal protocol packets ---> There are many opaque errors in the logs when i checked it 

Opaque errors:
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0     : 9-out of flooding scope        466   : 10-out of flooding scope
0     : 11-out of flooding scope       0     : Unknown TLV type

Root Cause
Huawei S9700 disables opaque capability, So when Cisco send opaque packets, it doesn’t receive ACK packets (S9700 dropped it because opaque capability disabled).

If the un-received ACK packets reach the threshold, Cisco device will send 1-Wayhello to reset OSPF session.

From the analysis above,
This seems to be compatibility issue between Huawei and Cisco
Solution
add the following command 
********************************
<Quidway> system-view
[Quidway] ospf 10
[Quidway-ospf-10] opaque-capability enable
Suggestions
I Suggest to enable this feature (opaque-capability) by default.

END