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Cisco Bug: CSCsy75976 - AIS: Disabe blocked port triggers duplicate AIS error and doesn't clear

Last Modified

Feb 09, 2017

Products (1)

  • Cisco Catalyst 6000 Series Switches

Known Affected Releases


Description (partial)


Remote Fault Indication (Dying gasp,  Link Fault, Critical Event) from peer on a spanning tree blocked port would generate AIS protocol data unit at configured maintenance domain level for all the active vlans.


On a Catalyst 6500 series switches running software version 8.7(3) with ethernet-cfm AIS enabled.
In this scenario, since AIS is generated much earlier before spanning tree or MVRP
Converges, it is not feasible to stop the trigger of AIS in the first place. We can 
Still attempt to stop AIS after backup path becomes active and traffic resumes, 
But some number of FALSE notifications does reach to the customer domain MEPs
Which might not be desirable. Moreover, we are not familiar with how other vendors
Are handling these cases and no other BUs are supporting this configuration too as of now.
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Bug Details Include

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