Cisco Systems IC-23 manual Configuring a Fiber Distributed Data Interface, IC-37

Configuring LAN Interfaces

Configuring a Fiber Distributed Data Interface

EtherChannel even if the line protocol goes down. This can result in unpredictable behavior. The implementation of the Port Aggregation Protocol in a subsequent release of this feature will remove the dependency on keepalives.

See the “LAN Interface Configuration Examples” section for configuration examples.

You can monitor the status of the Fast EtherChannel interface by using the show interfaces port-channelEXEC command.

Configuring a Fiber Distributed Data Interface

The Fiber Distributed Data Interface (FDDI) is an ANSI-defined standard for timed 100-Mbps token passing over fiber-optic cable. FDDI is not supported on access servers.

An FDDI network consists of two counter-rotating, token-passing fiber-optic rings. On most networks, the primary ring is used for data communication and the secondary ring is used as a hot standby. The FDDI standard sets a total fiber length of 200 kilometers. (The maximum circumference of the FDDI network is only half the specified kilometers because of the wrapping or looping back of the signal that occurs during fault isolation.)

The FDDI standard allows a maximum of 500 stations with a maximum distance between active stations of two kilometers when interconnecting them with multimode fiber or ten kilometers when interconnected via single mode fiber, both of which are supported by our FDDI interface controllers. The FDDI frame can contain a minimum of 17 bytes and a maximum of 4500 bytes. Our implementation of FDDI supports Station Management (SMT) Version 7.3 of the X3T9.5 FDDI specification, offering a single MAC dual-attach interface that supports the fault-recovery methods of the dual attachment stations (DASs). The mid-range platforms also support single attachment stations (SASs).

Refer to the Cisco Product Catalog for specific information on platform and interface compatibility. For installation and configuration information, refer to the installation and configuration publication for the appropriate interface card or port adapter.

Source-Route Bridging over FDDI on Cisco 4000-M, Cisco 4500-M, and Cisco 4700-M Routers

Source-route bridging (SRB) is supported on the FDDI interface to the Cisco 4000-M, Cisco 4500-M, and Cisco 4700-M routers. For instructions on configuring autonomous FDDI SRB or fast-switching SRB over FDDI, refer to the “Configuring Source-Route Bridging” chapter of the Cisco IOS Bridging and IBM Networking Configuration Guide.

Particle-Based Switching of Source-Route Bridge Packets on Cisco 7200 Series Routers

Source-route bridging (SRB) is supported over Fiber Distributed Data Interface (FDDI).

Particle-based switching is supported for SRB packets (over FDDI and Token Ring) by default.

Particle-based switching adds scatter-gather capability to SRB to improve performance. Particles represent a communications data packet as a collection of noncontiguous buffers. The traditional Cisco IOS packet has a packet type control structure and a single contiguous data buffer. A particle packet has the same packet type control structure, but also maintains a queue of particle type structures, each of which manages its own block.

Cisco IOS Interface Configuration Guide

IC-37