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Clearing ANCP Access Loops

You can force a reset of a particular Layer 2 wholesale connection while the access loop is operationally up by issuing the clear ancp access-loop command. The command initiates logout of an ANCP-triggered, dynamic VLAN session, which includes issuing RADIUS Accounting-Stop messages for the session, and removal of the dynamic VLAN logical interface and active services. After the session is cleaned up, the command initiates re-authorization of the dynamic VLAN session, simulating receipt of an ANCP Port Up message. The session may then be recreated.

You must identify the access loop by either the IP address of the ANCP neighbor or the name of the subscriber-facing physical interface. You must also specify one or more of the following additional identifiers for the access loop:

  • circuit-id—The value of the ANCP Access-Loop-Circuit-ID TLV.

  • remote-id—The value of the ANCP Access-Loop-Remote-ID TLV.

  • outer-vlan-id—The value of the ANCP Access-Aggregation-Circuit-ID-binary TLV.


The clear ancp access-loop command has no effect in the following circumstances:

  • The access line is reported to be down, as indicated by an ANCP Port Down message, when the command is issued.

  • An ANCP Port Down message is received for the access line while the dynamic VLAN logical interface and the services are being removed. In this case, re-authorization of the dynamic VLAN cannot take place until an ANCP Port Up message is received for that access line.

  • A conventionally autosensed dynamic VLAN (for the access provider’s own subscriber sessions) has matching access loop attributes. In this case, the Layer 2 wholesale access line for which the command is intended is cleared, but the other VLAN, for sessions owned by the access-provider, is cleared as expected.

To clear an ANCP access loop:

  • Identify the loop by the neighbor’s IP address or the access-facing physical interface, and one or more of the ACI, ARI, and outer VLAN ID.