2-3 Token Ring Interfaces

  • Token Ring networks can operate at either 4 Mbps or 16 Mbps.

  • A token is passed around a ring network, allowing the owner of the token to transmit a frame.

  • One station on each ring is elected the active ring monitor. Other stations can participate as backup ring monitors . Ring monitors provide housekeeping functions for the entire ring.

  • All stations on a ring must operate at the same speed. If a station enters the ring at an incorrect speed, it causes the entire ring to beacon and become nonoperational. Beacon frames are sent during network fault conditions to inform other stations of the ring status. An autoreconfiguration process is attempted by the stations within the faulty part of the ring in an effort to bypass the fault.

  • By default, a station captures the token, transmits a frame (if needed), and waits for the frame to return around the ring before releasing the token. Early token release allows a transmitting station to immediately release the token before seeing the frame return. This allows more ring bandwidth.

Configuration

  1. Set the interface's ring speed:

     (interface)  ring-speed  {  4   16  } 

    The interface can be configured for either 4 Mbps or 16 Mbps.

  2. (Optional) Enable early token release:

     (interface)  early-token-release  

    If enabled, the interface can transmit a frame and immediately release the token.

Example

A Token Ring interface is configured with IP and IPX addresses. In addition, the ring will operate at 16 Mbps and will support early token release.

  interface tokenring 4/0   ring-speed 16   early-token-release   ip address 10.1.1.1 255.255.255.0   ipx network 1234  


Cisco Field Manual[c] Router Configuration
Cisco Field Manual[c] Router Configuration
ISBN: 1587050242
EAN: N/A
Year: 2005
Pages: 185

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