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Cisco Bug: CSCvv16597 - Upgrading to 16.9.5 breaks the xconnect functionality of forwarding Superior BPDUs in ASR1002-X

Last Modified

Jul 31, 2020

Products (1)

  • Cisco ASR 1000 Series Aggregation Services Routers

Known Affected Releases


Description (partial)

ASR1002-X not forwarding Superior STP BPDUs after upgrade to 16.9.5
Issue not seeing in version 03.16.10.S

When upgrading ASR1002-X to 16.9.5, the ASR1002-X stops forwarding Superior BPDU towards the MPLS cloud.
Other control plane layer 2 protocols such as CDP, LACP, STP (Inferior BPDUs) are not affected.
This causes the 6500-1 to not communicate with 6500-2 in the STP domain, and port goes into P2P Dispute.


6500-1 ---ASR1002-X--------MPLS Cloud -----ASR1001 ----6500-2

Use old legacy xconnect commands on the ASRs. i.e:
interface GigabitEthernet0/0/1
 mtu 9000
 no ip address
 negotiation auto
 cdp enable
 xconnect x.x.x.x x encapsulation mpls

Root bridge of STP should be connected to the ASR1002-X.
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