Table Of Contents
Configuring an Ethernet or Fast Ethernet Interface
Ethernet and Fast Ethernet Interface Configuration Task List
Specifying an Ethernet or Fast Ethernet Interface
Specifying an Ethernet Encapsulation Method
Specifying Full-Duplex Operation
Specifying the Media and Connector Type
Extending the 10BASE-T Capability
Configuring Fast Ethernet 100BASE-T
Configuring PA-12E/2FE Port Adapter
Configuring the 100VG-AnyLAN Port Adapter
Fast EtherChannel Configuration Task List
Configuring the Port-Channel Interface
Configuring the Fast Ethernet Interfaces
Configuring a Fiber Distributed Data Interface
Source-Route Bridging over FDDI on Cisco 4000-M, Cisco 4500-M, and Cisco 4700-M Routers
Particle-Based Switching of Source-Route Bridge Packets on Cisco 7200 Series Routers
Using Connection Management Information
Enabling FDDI Bridging Encapsulation
Enabling Full-Duplex Mode on the FDDI
Setting the Token Rotation Time
Setting the Transmission Valid Timer
Controlling the Transmission Timer
Modifying the FDDI Timeout Timer
Controlling SMT Frame Processing
Enabling Duplicate Address Checking
Setting FDDI Frames Per Token Limit
Controlling the FDDI SMT Message Queue Size
Preallocating Buffers for Bursty FDDI Traffic
Disabling or Enabling Automatic Receiver Polarity Reversal
Disabling or Enabling the Link Test Function
Enabling Source Address Control
Enabling SNMP Illegal Address Trap
Configuring a LAN Extender Interface
Connecting a LAN Extender to a Core Router
Expanded View of the Connection to a Core Router
Management of the LAN Extender Interface
Installing a LAN Extender at a Remote Site
Upgrading Software for the LAN Extender
LAN Extender Interface Configuration Task List
Configuring and Creating a LAN Extender Interface
Controlling the Sending of Commands to the LAN Extender
Shutting Down and Restarting the LAN Extender's Ethernet Interface
Downloading a Software Image to the LAN Extender
Troubleshooting the LAN Extender
Configuring a Token Ring Interface
Particle-Based Switching of Source-Route Bridge Packets on Cisco 7200 Series Routers
Dedicated Token Ring Port Adapter
Token Ring Interface Configuration Task List
Specifying a Token Ring Interface
Configuring PCbus Token Ring Interface Management
Enabling Token Ring Concentrator Port
Monitoring and Maintaining the Port
LAN Interface Configuration Examples
Ethernet Encapsulation Enablement Example
Full Duplex Enablement Operation Example
PA-12E/2FE Port Configuration Examples
PA-VG100 Port Adapter Configuration Example
Fast EtherChannel Configuration Examples
FDDI Frames Configuration Example
Source Address for an Ethernet Hub Port Configuration Examples
SNMP Illegal Address Trap Enablement for Hub Port Example
LAN Extender Enablement Interface Example
LAN Extender Interface Access List Examples
Ethernet Type Code Filtering Example
Configuring LAN Interfaces
Use the information in this chapter to configure LAN interfaces supported on Cisco routers and access servers.
This chapter describes the processes for configuring LAN interfaces in the following sections:
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Configuring an Ethernet or Fast Ethernet Interface
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For examples of configuration tasks, see the "LAN Interface Configuration Examples" section.
For hardware technical descriptions and information about installing interfaces, refer to the hardware installation and configuration publication for your product. For a complete description of the LAN interface commands used in this chapter, refer to the "Interface Commands" chapter of the Cisco IOS Interface Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Configuring an Ethernet or Fast Ethernet Interface
Cisco supports both 10-Mbps Ethernet and 100-Mbps Fast Ethernet.
Support for the 10-Mbps and 100-Mbps Ethernet interface is supplied on various Ethernet network interface cards or systems.
The Fast Ethernet NP-1FE module, for example, provides the following benefits:
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With the Catalyst 3000 or Catalyst 5000 system, the Fast Ethernet processor can be used to aggregate up to twelve 10-Mbps LANs and give them high-speed access to such Layer 3 routing services as providing firewalls and maintaining access lists.
Cisco 7200 series routers support an I/O controller with an RJ-45 interface. You can configure the optional Fast Ethernet port for use at 100-Mbps full-duplex or half-duplex operation (half duplex is the default). The Fast Ethernet port is equipped with either a single MII receptacle or an MII receptacle and an RJ-45 receptacle. To support this new feature, the media-type interface command has been modified. The media-type interface command now supports two options:
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Second-generation Fast Ethernet Interface Processors (FEIP2-DSW-2TX and FEIP2-DSW-2FX) are available on Cisco 7500 series routers and on Cisco 7000 series routers with the 7000 Series Route Switch Processor (RSP7000) and 7000 Series Chassis Interface (RSP7000CI). The FEIP2-DSW is a dual-port, fixed-configuration interface processor that provides two 100-Mbps Fast Ethernet (FE) interfaces. Each interface on the FEIP2-DSW supports half-duplex only for a maximum aggregate bandwidth of 200 Mbps.
Refer to the Cisco Product Catalog for specific platform and hardware compatibility information.
Use the show interfaces, show controllers mci, and show controllers cbus EXEC commands to display the Ethernet port numbers. These commands provide a report for each interface supported by the router or access server.
Use the show interface fastethernet command to display interface statistics, and use the show controller fastethernet to display the information about the Fast Ethernet controller chip. The output shows statistics, including information about initialization block information, transmit ring, receive ring and errors.
For information on how to configure Fast EtherChannel, see the tasks listed in the "Configuring Fast EtherChannel" section.
Ethernet and Fast Ethernet Interface Configuration Task List
Perform the tasks in the following sections to configure features on an Ethernet or Fast Ethernet interface:
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Specifying an Ethernet or Fast Ethernet Interface
To specify an Ethernet interface and enter interface configuration mode, use one of the following commands in global configuration mode:
Use the show interfaces fastethernet command to display the Fast Ethernet slots and ports. The Fast Ethernet NIM and the FEIP default to half-duplex mode.
Specifying an Ethernet Encapsulation Method
Currently, there are three common Ethernet encapsulation methods:
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The encapsulation method you use depends upon the routing protocol you are using, the type of Ethernet media connected to the router or access server, and the routing or bridging application you configure.
Establish Ethernet encapsulation of IP packets by using one of the following commands in interface configuration mode:
encapsulation arpa
Selects ARPA Ethernet encapsulation.
encapsulation sap
Selects SAP Ethernet encapsulation.
encapsulation snap
Selects SNAP Ethernet encapsulation.
For an example of selecting Ethernet encapsulation for IP, see the "Ethernet Encapsulation Enablement Example" section.
Specifying Full-Duplex Operation
The default is half-duplex mode on the FEIP2-DSW-2FX. To enable full-duplex mode on the FEIP2-DSW-2FX (for a maximum aggregate bandwidth of 200 Mbps), use either of the following commands in interface configuration mode:
full-duplex
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no half-duplex
Enables full-duplex on the Fast Ethernet interface of the FEIP2-DSW-2FX.
For an example to enable full-duplex mode on Fast Ethernet, see the "Full Duplex Enablement Operation Example" section.
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Specifying the Media and Connector Type
You can specify that the Ethernet network interface module (NIM) on the Cisco 4000 series routers use either the default of an AUI and a 15-pin connector, or 10BASE-T and an RJ-45 connector. To do so, use one of the following commands in interface configuration mode:
media-type aui
Selects a 15-pin Ethernet connector.
media-type 10baset
Selects an RJ-45 Ethernet connector.
The default media connector type is an RJ-45 or SC (fiber-optic) connector. You can specify that the interface uses either an MII connector, or an RJ-45 or SC (fiber-optic) connector (this is the default). To do so, use one of the following commands in interface configuration mode:
media-type mii
Selects an MII Ethernet connector.
media-type 100basex
Selects an RJ-45 Ethernet connector for the FEIP2-DSW-2TX or an SC connector for the FEIP2-DSW-2FX.
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Extending the 10BASE-T Capability
On a Cisco 4000 series or Cisco 4500 series routers, you can extend the twisted-pair 10BASE-T capability beyond the standard 100 meters by reducing the squelch (signal cutoff time). This feature applies only to the LANCE controller 10BASE-T interfaces. LANCE is the AMD controller chip for the Cisco 4000 and Cisco 4500 Ethernet interface.
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To reduce squelch, use the first command in the following table in interface configuration mode. You can later restore the squelch by using the second command.
Configuring Fast Ethernet 100BASE-T
You must configure the Fast Ethernet 100BASE-T interface on a Cisco AS5300 so that it can be recognized as a device on the Ethernet LAN. The Fast Ethernet interface supports 10- and 100-Mbps speeds with the 100BASE-T and 10BASE-T routers, hubs, and switches.
To configure the interface, use the following commands beginning in privileged EXEC mode:
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configure terminal
Enters global configuration mode.
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interface fastethernet number
Enters Fast Ethernet interface configuration mode.
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ip address address subnet-mask
Assigns an IP address and subnet mask to the interface.
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speed {10 | 100 | auto}
Assigns a speed to the interface. The default is 100 Mbps.1
For relationship between duplex and speed command options, see Table 3.
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duplex {full | half | auto}
Sets up the duplex configuration on the Fast Ethernet interface. The default is half duplex.1
For relationship between duplex and speed command options, see Table 3.
1 The auto option automatically negotiates the speed based on the speed and the peer router, hub, or switch media.
To use the auto-negotiation capability (that is, to detect speed and duplex modes automatically), you must set both speed and duplex to auto. Setting the speed to auto negotiates speed only, and setting duplex to auto negotiates duplex only. Table 3 describes the access server's performance for different combinations of the duplex and speed command options. The specified duplex command option plus the specified speed command option produces the resulting system action.
Configuring PA-12E/2FE Port Adapter
The PA-12E/2FE Ethernet switch port adapter provides Cisco 7200 series routers with up to twelve 10-Mbps and two 10/100-Mbps switched Ethernet (10BASE-T) and Fast Ethernet (100BASE-TX) interfaces for an aggregate bandwidth of 435 Mbps, full-duplex. The PA-12E/2FE port adapter supports the Ethernet, IEEE 802.3, and IEEE 802.3u specifications for 10-Mbps and 100-Mbps transmission over UTP cables.
The PA-12E/2FE port adapter offloads Layer 2 switching from the host CPU by using store-and-forward or cut-through switching technology between interfaces within the same virtual LAN (VLAN) on the PA-12E/2FE port adapter. The PA-12E/2FE port adapter supports up to four VLANs (bridge groups).
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All interfaces on the PA-12E/2FE port adapter support autosensing and autonegotiation of the proper transmission mode (half-duplex or full-duplex) with an attached device. The first two PA-12E/2FE interfaces (port 0 and port 1) also support autosensing and autonegotiation of the proper connection speed (10-Mbps or 100-Mbps) with an attached device. If an attached device does not support autosensing and autonegotiation of the proper transmission mode, the PA-12E/2FE interfaces attached to the device automatically enter half-duplex mode. Use the show system:running-config command to determine if a PA-12E/2FE interface is autosensing and autonegotiating the proper transmission mode with an attached device. Use the full-duplex and the half-duplex commands to change the transmission mode of a PA-12E/2FE interface. After changing the transmission mode, use the show interfaces command to verify the interface's transmission mode.
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To configure the PA-12E/2FE port adapter, perform the tasks in the following sections:
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For detailed information about booting from a network using TFTP, loading a system image from a network server, and configuring the Spanning-Tree Protocol on your Cisco 7200 series router, refer to the PA-12E/2FE Ethernet Switch Port Adapter book that accompanies the hardware and to the Cisco IOS Bridging and IBM Networking Configuration Guide.For information on other commands that can be used to configure a PA-12E/2FE port adapter, refer to the "Interfaces Commands" chapter in the Cisco IOS Interface Command Reference. For information on bridging, refer to the "Configuring Transparent Bridging" chapter in the Cisco IOS Bridging and IBM Networking Configuration Guide.
For PA-12E/2FE port adapter configuration examples, see the "PA-12E/2FE Port Configuration Examples" section.
Configuring the PA-12E/2FE Port Adapter
This section provides instructions for a basic configuration. You might also need to enter other configuration commands depending on the requirements for your system configuration and the protocols you plan to route on the interface. For complete descriptions of configuration commands and the configuration options available, refer to the other configuration guides in the Cisco IOS documentation set.
To configure the interfaces on the PA-12E/2FE port adapter, use the following commands in global configuration mode:
To enable integrated routing and bridging on the bridge groups, use the following commands beginning in global configuration mode:
Monitoring and Maintaining the PA-12E/2FE Port Adapter
After configuring the new interface, you can display its status and verify other information. To display information about the PA-12E/2FE port adapter, use the following commands in EXEC mode:
Configuring Bridge Groups Using the 12E/2FE VLAN Configuration WebTool
The 12E/2FE VLAN Configuration WebTool, shown in Figure 2, is a web browser-based Java applet that displays configured interfaces and bridge groups for PA-12E/2FE port adapters installed in Cisco routers. With the WebTool you can perform the following tasks:
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You can access the 12E/2FE VLAN Configuration WebTool from your router's home page. For complete procedures on how to use the VLAN Configuration WebTool, refer to the PA-12E/2FE Ethernet Switch Port Adapter book that accompanies the hardware.
Figure 2 Example Home Page for a Cisco 7200 Series Router (Cisco 7206 Shown)
All Cisco routers running Cisco IOS Release 11.0 or later have a home page. All Cisco router home pages are password protected. Contact your network administrator if you do not have the name or password for your Cisco 7200 series router.
If your router has an installed PA- 12E/2FE port adapter, the 12E/2FE VLAN Configuration WebTool shown in Figure 2 can be accessed from the router's home page using a Java-enabled web browser.
Configuring the 100VG-AnyLAN Port Adapter
The 100VG-AnyLAN port adapter (PA-100VG) is available on Cisco 7200 series routers and on Cisco 7500 series routers.
The PA-100VG provides a single interface compatible with and specified by IEEE 802.12 to support 100 Mbps over Category 3 or Category 5 unshielded twisted-pair (UTP) cable with RJ-45 terminators. The PA-100VG supports 802.3 Ethernet packets and can be monitored with the IEEE 802.12 Interface MIB.
To configure the PA-100VG port adapter, use the following commands beginning in global configuration mode:
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Configuring the PA-100VG interface is similar to configuring an Ethernet or Fast Ethernet interface. To display information about the 100VG-AnyLAN port adapter, use the show interfaces vg-anylan EXEC command.
Configuring Fast EtherChannel
The Fast EtherChannel feature allows multiple Fast Ethernet point-to-point links to be bundled into one logical link to provide bidirectional bandwidth of up to 800 Mbps. Fast EtherChannel builds on standards-based 802.3 full-duplex Fast Ethernet to provide fault-tolerant, high-speed links between switches, routers, and servers. This feature can be configured between Cisco 7500 series routers and Cisco 7000 series routers with the 7000 Series Route Switch Processor (RSP7000) and 7000 Series Chassis Interface (RSP7000CI) or between a Cisco 7500 series router or a Cisco 7000 series router with the RSP7000 and RSP700CI and a Catalyst 5000 switch.
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Fast EtherChannel provides higher bidirectional bandwidth, redundancy, and load sharing. Up to four Fast Ethernet interfaces can be bundled in a port-channel, and the router or switch can support up to four port-channels. The Fast EtherChannel feature is capable of load balancing traffic across the Fast Ethernet links. Unicast, broadcast, and multicast traffic is distributed across the links providing higher performance and redundant parallel paths. In the event of a link failure, traffic is redirected to remaining links within the Fast EtherChannel without user intervention.
In this release of the Fast EtherChannel feature, IP traffic is distributed over the port-channel interface while traffic from other routing protocols is sent over a single link. Bridged traffic is distributed based on the Layer 3 information in the packet. If the Layer 3 information does not exist in the packet, the traffic is sent over the first link.
Fast EtherChannel supports all features currently supported on the Fast Ethernet interface. You must configure these features on the port-channel interface rather than on the individual Fast Ethernet interfaces. Fast EtherChannel connections are fully compatible with Cisco IOS virtual LAN (VLAN) and routing technologies. The Inter-Switch Link (ISL) VLAN trunking protocol can carry multiple VLANs across a Fast EtherChannel, and routers attached to Fast EtherChannel links can provide full multiprotocol routing with support for host standby using Host Standby Router Protocol (HSRP).
The port-channel (consisting of up to four Fast Ethernet interfaces) is treated as a single interface. Port-channel is used in the Cisco IOS software to maintain compatibility with existing commands on the Catalyst 5000 switch. You create the Fast EtherChannel by using the interface port-channel interface configuration command. You can assign up to four Fast Ethernet interfaces to a port-channel by using the channel-group interface configuration command.
Fast EtherChannel also supports the following two features:
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For more information about configuring HSRP, refer to the "Configuring IP Services" chapter in the Cisco IOS IP and IP Routing Configuration Guide.•
For more information about configuring CEF, refer to the "Cisco Express Forwarding" chapter in the Cisco IOS Switching Services Configuration Guide.For information on how to configure Ethernet or Fast Ethernet, see the tasks listed in the "Configuring an Ethernet or Fast Ethernet Interface" section.
Fast EtherChannel Configuration Task List
Perform the tasks in the following sections to configure Fast EtherChannel. To configure Fast EtherChannel, perform the following required steps:
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For information on other configuration tasks for the Fast EtherChannel, see the "Configuring an Ethernet or Fast Ethernet Interface" section.
For information on other commands that can be used by the Fast EtherChannel, refer to the other configuration guides in the Cisco IOS documentation set.
Configuring the Port-Channel Interface
To configure the port-channel interface, use the following commands beginning in global configuration mode:
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Configuring the Fast Ethernet Interfaces
To assign the Fast Ethernet interfaces to the Fast EtherChannel, use the following commands beginning in global configuration mode:
Caution
To remove a Fast Ethernet interface from a Fast EtherChannel, use the following commands beginning in global configuration mode:
The Cisco IOS software automatically removes a Fast Ethernet interface from the Fast EtherChannel if the interface goes down, and the software automatically adds the Fast Ethernet interface to the Fast EtherChannel when the interface is back up.
Currently, Fast EtherChannel relies on keepalives to detect whether the line protocol is up or down. Keepalives are enabled by default on the Fast Ethernet interfaces. If the line protocol on the interface goes down because it did not receive a keepalive signal, the Fast EtherChannel detects that the line protocol is down and removes the interface from the Fast EtherChannel. However, if the line protocol remains up because keepalives are disabled on the Fast Ethernet interface, the Fast EtherChannel cannot detect this link failure (other than a cable disconnect) and does not remove the interface from the Fast 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-channel EXEC 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.
The scatter-gather architecture used by particle-based switching provides the following advantages:
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For information about configuring SRB over FDDI, refer to the "Configuring Source-Route Bridging" chapter of the Cisco IOS Bridging and IBM Networking Configuration Guide.
Using Connection Management Information
Connection management (CMT) is an FDDI process that handles the transition of the ring through its various states (off, on, active, connect, and so on) as defined by the X3T9.5 specification. The FIP provides CMT functions in microcode.
A partial sample output of the show interfaces fddi command follows, along with an explanation of how to interpret the CMT information in the output.
Phy-A state is active, neighbor is B, cmt signal bits 08/20C, status ALSPhy-B state is active, neighbor is A, cmt signal bits 20C/08, status ILSCFM is thru A, token rotation 5000 usec, ring operational 0:01:42Upstream neighbor 0800.2008.C52E, downstream neighbor 0800.2008.C52EThe show interfaces fddi example shows that Physical A (Phy-A) completed CMT with its neighbor. The state is active and the display indicates a Physical B-type neighbor.
The sample output indicates CMT signal bits 08/20C for Phy-A. The transmit signal bits are 08. Looking at the PCM state machine, 08 indicates that the port type is A, the port compatibility is set, and the LCT duration requested is short. The receive signal bits are 20C, which indicate the neighbor type is B, port compatibility is set, there is a MAC on the port output, and so on.
The neighbor is determined from the received signal bits, as follows:
Interpreting the bits in the diagram above, the received value equals 0x20C. Bit positions 1 and 2 (0 1) indicate a Physical B-type connection.
The transition states displayed indicate that the CMT process is running and actively trying to establish a connection to the remote physical connection. The CMT process requires state transition with different signals being transmitted and received before moving on to the state ahead as indicated in the PCM state machine. The ten bits of CMT information are transmitted and received in the Signal State. The NEXT state is used to separate the signaling performed in the Signal State. Therefore, in the preceding sample output, the NEXT state was entered 11 times.
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The CFM state is through A in the sample output, which means this interface's Phy-A has successfully completed CMT with the Phy-B of the neighbor and Phy-B of this interface has successfully completed CMT with the Phy-A of the neighbor.
The display (or nondisplay) of the upstream and downstream neighbor does not affect the ability to route data. Since the upstream neighbor is also its downstream neighbor in the sample, there are only two stations in the ring: the network server and the router at address 0800.2008.C52E.
FDDI Configuration Task List
Perform the tasks in the following sections to configure an FDDI interface:
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Specifying a FDDI
To specify an FDDI interface and enter interface configuration mode, use one of the following commands in global configuration mode:
interface fddi number
Begins interface configuration.
interface fddi slot/port
Begins interface configuration for the Cisco 7200 or Cisco 7500 series routers.
Enabling FDDI Bridging Encapsulation
Cisco FDDI by default uses the SNAP encapsulation format defined in RFC 1042. It is not necessary to define an encapsulation method for this interface when using the FIP.
FIP fully supports transparent and translational bridging for the following configurations:
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Enabling FDDI bridging encapsulation places the FIP into encapsulation mode when doing bridging. In transparent mode, the FIP interoperates with earlier versions of encapsulating interfaces when performing bridging functions on the same ring. When using the FIP, you can specify the encapsulation method by using the following command in interface configuration mode:
When you are doing translational bridging, use routing for routable protocols and use translational bridging for the rest (such as LAT).
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We are currently aware of problems with the following protocols when bridged between Token Ring and other media: AppleTalk, DECnet, IP, Novell IPX, Phase IV, VINES, and XNS. Further, the following protocols might have problems when bridged between FDDI and other media: Novell IPX and XNS. We recommend that these protocols be routed whenever possible.
Enabling Full-Duplex Mode on the FDDI
To enable full-duplex mode on the PA-F/FD-SM and PA-F/FD-MM port adapters, use one of the following commands in interface configuration mode:
full-duplex
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no half-duplex
Enables full-duplex on the FDDI interface of the PA-F/FD-SM and PA-F/FD-MM port adapter.
Setting the Token Rotation Time
You can set the FDDI token rotation time to control ring scheduling during normal operation and to detect and recover from serious ring error situations. To do so, use the following command in interface configuration mode:
The FDDI standard restricts the allowed time to be greater than 4000 microseconds and less than 165,000 microseconds. As defined in the X3T9.5 specification, the value remaining in the token rotation timer (TRT) is loaded into the token holding timer (THT). Combining the values of these two timers provides the means to determine the amount of bandwidth available for subsequent transmissions.
Setting the Transmission Valid Timer
You can set the transmission timer to recover from a transient ring error by using the following command in interface configuration mode:
Controlling the Transmission Timer
You can set the FDDI control transmission timer to control the FDDI TL-Min time, which is the minimum time to transmit a Physical Sublayer or PHY line state before advancing to the next Physical Connection Management or PCM state as defined by the X3T9.5 specification. To do so, use the following command in interface configuration mode:
Modifying the C-Min Timer
You can modify the C-Min timer on the PCM from its default value of 1600 microseconds by using the following command in interface configuration mode:
Modifying the TB-Min Timer
You can change the TB-Min timer in the PCM from its default value of 100 ms. To do so, use the following command in interface configuration mode:
Modifying the FDDI Timeout Timer
You can change the FDDI timeout timer in the PCM from its default value of 100 ms. To do so, use the following command in interface configuration mode:
Controlling SMT Frame Processing
You can disable and enable SMT frame processing for diagnostic purposes. To do so, use one of the following commands in interface configuration mode:
no fddi smt-frames
Disables SMT frame processing.
fddi smt-frames
Enables SMT frame processing.
Enabling Duplicate Address Checking
You can enable the duplicate address detection capability on the FDDI. If the FDDI finds a duplicate address, it displays an error message and shuts down the interface. To enable duplicate address checking, use the following command in interface configuration mode:
Setting the Bit Control
You can set the FDDI bit control to control the information transmitted during the Connection Management (CMT) signaling phase. To do so, use the following command in interface configuration mode:
Controlling the CMT Microcode
You can control whether the CMT onboard functions are on or off. The FIP provides CMT functions in microcode. These functions are separate from those provided on the processor card and are accessed through EXEC commands.
The default is for the FIP CMT functions to be on. A typical reason to disable is when you work with new FDDI equipment and have problems bringing up the ring. If you disable the CMT microcode, the following actions occur:
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