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• Checking and Clearing MAC Rewrite Error Conditions on an Interface    

• Related Topics
• Layer 2 Protocol Tunneling Through a Network Overview
• MAC Address Rewriting Enabled for Layer 2 Protocol Tunneling
• Layer 2 Protocol Tunnel Interface
• Layer 2 Protocol to be Tunneled
• Configuring Layer 2 Protocol Tunneling

Checking and Clearing MAC Rewrite Error Conditions on an Interface

On an MX Series router with a spanning-tree protocol enabled, the detection of a possible bridging loop from spanning-tree protocol operation can raise a bridge protocol data unit (BPDU) error condition on the affected spanning-tree instance interface.

To clear a BPDU error condition on a spanning-tree instance interface:

1. Check the status of the interface by using the show interfaces interface-name operational mode command.

   • The interface is not blocked if the value in the Physical interface includes Enabled, Physical link is Up and the value of the BPDU Error field is None.
   • The interface is blocked if the value in the Physical interface field is Enabled, Physical link is Down and the value in the BPDU Error field is Detected.
2. If the interface is blocked, you can clear the blocked status of an interface by using the clear error bpdu interface interface-name command.

   Note: When you configure BPDU protection on individual interfaces (as opposed to on all the edge ports of the bridge), you can use the disable-timeout seconds option to specify that a blocked interface is automatically cleared after the specified time interval elapses (unless the interval is 0). For configuration details, see Configuring BPDU Protection on Individual Interfaces.