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    Unblocking an Interface That Receives BPDUs in Error

    Note: BPDU block protection is disabled on Node devices.

    Devices use bridge protocol data unit (BPDU) protection on interfaces to prevent them from receiving BPDUs that could trigger a spanning-tree misconfiguration. If BPDUs are received on a BPDU-protected interface, the interface transitions to a blocking state and stops forwarding frames.

    After you fix the misconfiguration that triggered the sending of BPDUs to an interface, you can unblock the interface and return it to service.

    Note: This task describes how to use both the original CLI and the Enhanced Layer 2 Software (ELS) CLI. For ELS details, see Getting Started with Enhanced Layer 2 Software.

    To unblock an interface after fixing the misconfiguration that triggered the BPDUs and return it to service:

    • (Original CLI) Automatically unblock an interface by configuring a timer that expires (here, the interface is xe-0/0/6):
      [edit ethernet-switching-options]
      user@switch# set bpdu-block disable-timeout 30 interface xe-0/0/6
    • (ELS CLI) Automatically unblock an interface by configuring a timer that expires (here, the interface is xe-0/0/6):
      [edit protocols layer2-control]
      user@switch# set bpdu-block disable-timeout 30 interface xe-0/0/6
    • Manually unblock an interface using the operational mode command:
      user@switch> clear error bpdu interface xe-0/0/6
    • Verify that the interface has been unblocked using the operational command:
      user@switch> show ethernet-switching interfaces xe-0/0/6
       Interface   State    VLAN members           Blocking 
      xe-0/0/6.0  down     default                unblocked
      

    Modified: 2016-04-29