Cisco Systems BC-109 User Manual
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Configuring Source-RouteBridging

This chapter describes source-routebridging (SRB) configuration tasks. For a discussion of remotesource-routebridging (RSRB) configuration tasks, refer to the “Configuring RemoteSource-RouteBridging” chapter in this publication.

For a complete description of the SRB commands mentioned in this chapter, refer to the “Source-RouteBridging Commands” chapter in theBridging and IBM Networking Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.

SRB Configuration Task List

Perform the tasks in the following sections to configure SRB:

Configure Source-Route Bridging

Configure Bridging of Routed Protocols

Configure Translation between SRB and Transparent Bridging Environments

Configure NetBIOS Support

Configure LNM Support

Secure the SRB Network

Tune the SRB Network

Establish SRB Interoperability with Specific Token Ring Implementations

Monitor and Maintain the SRB Network

See the end of this chapter for “SRB Configuration Examples.”

Warning The Cisco IOS software issues a warning if a duplicate bridge definition exists in a router. You must remove an old bridge definition before adding a new bridge definition to a router configuration.

Configuring Source-RouteBridgingBC-109

Configure Source-RouteBridging

Configure Source-RouteBridging

Our implementation of source-routebridging enables you to connect two or more Token Ring networks using either Token Ring or Fiber Distributed Data Interface (FDDI) media.

The Cisco IOS software offers the ability to encapsulate source-routebridging traffic using RFC 1490 Bridged 802.5 encapsulation. This encapsulation provides SRB over Frame Relay functionality.

You can configure the Cisco IOS software for source-routebridging by performing the tasks in one of the first three sections and, optionally, the tasks in the last section:

Configure a Dual-Port Bridge

Configure a Multiport Bridge Using a Virtual Ring

Configure SRB over FDDI

Configure Fast-Switching SRB over FDDI

Configure SRB over Frame Relay

Enable the Forwarding and Blocking of Spanning-Tree Explorers

Enable the Automatic Spanning-Tree Function

Limit the Maximum SRB Hops

Configure a Dual-PortBridge

A dual-portbridge is the simplestsource-routebridging configuration. When configured as adual-portbridge, the access server or router serves to connect two Token Ring LANs. One LAN is connected through one port (Token Ring interface), and the other LAN is connected through the other port (also a Token Ring interface).Figure 45 shows adual-portbridge.

Figure 45 Dual-PortBridge

Token

T0

 

Token

Ring

 

T1

Ring

129

 

130

 

 

S1102a

To configure a dual-portbridge that connects two Token Rings, you must enablesource-routebridging on each of the Token Ring interfaces that connect to the two Token Rings. To enablesource-routebridging, use the following command in interface configuration mode for each of the Token Ring interfaces:

Command

Purpose

source-bridge local-ringbridge-numbertarget-ring

Enable local source-routebridging on

 

a Token Ring interface.

 

 

Note Ring numbers need to be unique across interfaces and networks, so that when you enablesource-routebridging over an interface the local and target rings are defined. Each node on the network will know if it is the target of explorer packets sent on the network.

BC-110 Bridging and IBM Networking Configuration Guide

Configure a Multiport Bridge Using a Virtual Ring

A dual-portbridge is a limitation imposed by IBM Token Ring chips; the chips can process only two ring numbers. If you have a router with two or more Token Ring interfaces, you can work around thetwo-ringnumber limitation. You can configure your router as multipledual-portbridges or as a multiport bridge using a virtual ring.

You can define several separate dual-portbridges in the same router. However, the routers on the LANs cannot haveany-to-anyconnectivity; that is, they cannot connect to every other router on the bridged LANs. Only the routers connected to thedual-portbridge can communicate with one another.Figure 46 shows two separatedual-portbridges(T0-T2andT1-T3)configured on the same router.

Figure 46 Multiple Dual-PortBridges

Token

Ring

T1

Token T2 T0

Ring

T3

Token

Ring

Token

Ring

S2323

To configure multiple dual-portsource-routebridges, use the following command in interface configuration mode for each Token Ring interface that is part of adual-portbridge:

Command

Purpose

source-bridge local-ringbridge-numbertarget-ring

Enable local source-routebridging on

 

a Token Ring interface.

 

 

If you want your network to use only SRB, you can connect as many routers as you need via Token Rings. Remember, source-routebridging requires you to bridge only Token Ring media.

Configure a Multiport Bridge Using a Virtual Ring

A better solution for overcoming the two-ringnumber limitation of IBM Token Ring chips is to configure a multiport bridge using a virtual ring. A virtual ring on a multiport bridge allows the router to interconnect three or more LANs withany-to-anyconnectivity; that is, connectivity between any of the routers on each of the three LANs is allowed. A virtual ring creates a logical Token Ring internal to the Cisco IOS software, which causes all the Token Rings connected to the router to be treated as if they are all on the same Token Ring. The virtual ring is called aring group. Figure 47 shows a multiport bridge using a virtual ring.

Configuring Source-RouteBridgingBC-111

Configure Source-RouteBridging

Figure 47 Multiport Bridge Using a Virtual Ring

 

Token

 

 

Ring

 

 

T1

 

Token

T2

 

Ring

Ring

T0 Token

group

 

Ring

 

 

T3

Token

Ring

S2324

To take advantage of this virtual ring feature, each Token Ring interface on the router must be configured to belong to the same ring group. For information about configuring a multiport bridge using a virtual ring, see the “Configure a Multiport Bridge Using a Virtual Ring” section later in this chapter.

To configure a source-routebridge to have more than two network interfaces, you must perform the following tasks:

Step 1 Define a ring group.

Step 2 Enablesource-route-bridgingand assign a ring group to a Token Ring interface.

Once you have completed these tasks, the router acts as a multiport bridge not as a dual-portbridge.

Note Ring numbers need to be unique across interfaces and networks.

Define a Ring Group in SRB Context

Because all IBM Token Ring chips can process only two ring numbers, we have implemented the concept of a ring group or virtual ring. A ring group is a collection of Token Ring interfaces in one or more routers that share the same ring number. This ring number is used just like a physical ring number, showing up in any route descriptors contained in packets being bridged. Within the context of a multiport bridge that uses SRB rather than RSRB, the ring group resides in the same router. See the “Configuring Remote Source-RouteBridging” chapter to compare ring groups in the SRB and RSRB context.

A ring group must be assigned a ring number that is unique throughout the network. It is possible to assign different Token Ring interfaces on the same router to different ring groups, if, for example, you plan to administer them as interfaces in separate domains.

To define or remove a ring group, use one of the following commands in global configuration mode:

Command

Purpose

source-bridgering-groupring-group

Define a ring group.

[virtual-mac-address]

 

 

 

no source-bridgering-groupring-group

Remove a ring group.

[virtual-mac-address]

 

 

 

BC-112 Bridging and IBM Networking Configuration Guide

Configure SRB over FDDI

Enable SRB and Assign a Ring Group to an Interface

After you have defined a ring group, you must assign that ring group to those interfaces you plan to include in that ring group. An interface can only be assigned to one ring group. To enable any-to-anyconnectivity among the end stations connected through this multiport bridge, you must assign the same target ring number to all Token Ring interfaces on the router.

To enable SRB and assign a ring group to an interface, use the following command in interface configuration mode:

Command

Purpose

source-bridge local-ringbridge-numbertarget-ring

Enable source-routebridging and

 

assign a ring group to a Token Ring

 

interface.

 

 

Configure SRB over FDDI

Cisco’s implementation of SRB expands the basic functionality to allow autonomous switching of SRB network traffic for FDDI interfaces, adding counters to SRB accounting statistics, and implementing process-levelswitching of SRB over FDDI. This functionality provides a significant increase in performance for Token Rings interconnected across an FDDI backbone (seeFigure 48).

SRB over FDDI is supported on the Cisco 4000-M,Cisco4500-M,Cisco4700-M,Cisco 7000 series, Cisco 7200 series, and Cisco 7500 routers.

Figure 48 Autonomous FDDI SRB

Token

FDDI

Token

Ring

Ring

Virtual ring

S3227

To configure autonomous FDDI SRB, use the following commands, beginning in global configuration mode:

Step

Command

Purpose

1

interface fddi slot/port

Configure an FDDI interface.

 

 

 

2

source-bridge local-ringbridge-number

Enable source-routebridging.

 

target-ring

 

 

 

 

3

source-bridgeroute-cachecbus

Enable autonomous switching.

 

 

 

Configuring Source-RouteBridgingBC-113

Configure Source-RouteBridging

Configure Fast-SwitchingSRB over FDDI

Fast-SwitchingSRB over FDDI enhances performance. For example, if you want to useaccess-lists,fast-switchingSRB over FDDI provides fast performance andaccess-listfilters capability.

To configure fast-switchingSRB over FDDI, use the following commands, beginning in global configuration mode:

Step

Command

Purpose

1

interface fddi slot/port

Configure an FDDI interface.

 

 

 

2

source-bridge local-ringbridge-number

Enable source-routebridging.

 

target-ring

 

 

 

 

3

source-bridgespanning

Enable source-bridgespanning.

 

 

 

4

source-bridgeroute-cache

Enable fast-switching.

 

 

 

5

multiring protocol-keyword

Enable the collection and use of RIF

 

 

information.

 

 

 

Configure SRB over Frame Relay

Cisco IOS software offers the ability to encapsulate source-routebridging traffic using RFC 1490 Bridged 802.5 encapsulation. This provides SRB over Frame Relay functionality that is interoperable with other vendors’ implementations of SRB over Frame Relay and with some vendors’ implementations of FRAS BAN.

Note In the initial release, SRB over Frame Relay does not support the Cisco IOS software proxy explorer, automaticspanning-tree,or LAN Network Manager functions.

To configure SRB over Frame Relay, use the following commands in interface configuration mode:

Step

Command

Purpose

1

interface serial number

Specify the serial port.

 

 

 

2

encapsulation frame-relay

Enable Frame Relay encapsulation.

 

 

 

3

interface serial slot/port.subinterface-number

Configure a Frame Relay

 

point-to-point

point-to-pointsubinterface.

 

 

 

4

frame-relayinterface-dlcidlci ietf

Configure a DLCI number for the

 

 

point-to-pointsubinterface.

 

 

 

5

source-bridge source-ring-numberbridge-number

Assign a ring number to the Frame

 

target-ring-numberconserve-ring

Relay permanent virtual circuit.

 

 

 

Enable the Forwarding and Blocking of Spanning-TreeExplorers

When trying to determine the location of remote destinations on a source-routebridge, the source device will need to send explorer packets. Explorer packets are used to collect routing information field (RIF) information. The source device can sendspanning-treeexplorers orall-routesexplorers. Note that some older IBM devices generate onlyall-routesexplorer packets, but many newer IBM devices are capable of generatingspanning-treeexplorer packets.

A spanning-treeexplorer packet is an explorer packet that is sent to a defined group of nodes that comprise a statically configured spanning tree in the network. In contrast, anall-routesexplorer packet is an explorer packet that is sent to every node in the network on every path.

BC-114 Bridging and IBM Networking Configuration Guide

Enable the Automatic Spanning-TreeFunction

Forwarding all-routesexplorer packets is the default. However, in complicatedsource-routebridging topologies, using this default can generate an exponentially large number of explorers that are traversing the network. The number of explorer packets becomes quite large because duplicate explorer packets are sent across the network to every node on every path. Eventually each explorer packet will reach the destination device. The destination device will respond to each of these explorer packets. It is from these responses that the source device will collect the RIF and determine which route it will use to communicate with the destination device. Usually, the route contained in the first returned response will be used.

The number of explorer packets traversing the network can be reduced by sending spanning-treeexplorer packets.Spanning-treeexplorer packets are sent to specific nodes; that is, to only the nodes on the spanning tree, not to all nodes in the network. You must manually configure thespanning-treetopology over which thespanning-treeexplorers are sent. You do this by configuring which interfaces on the routers will forwardspanning-treeexplorers and which interfaces will block them.

To enable forwarding of spanning-treeexplorers on an outgoing interface, use the following command in interface configuration mode:

Command

Purpose

source-bridgespanning

Enable the forwarding of

 

spanning-treeexplorer packets on an

 

interface.

 

 

Note While enabling the forwarding ofspanning-treeexplorer packets is not an absolute requirement, it is strongly recommended in complex topologies. Configuring an interface to block or forwardspanning-treeexplorers has no effect on how that interface handlesall-routesexplorer packets.All-routesexplorers can always traverse the network.

To block forwarding of spanning tree explorers on an outgoing interface, use the following command in interface configuration mode:

Command

Purpose

no source-bridgespanning

Block spanning-treeexplorer packets

 

on an interface.

 

 

Enable the Automatic Spanning-TreeFunction

The automatic spanning-treefunction supports automatic resolution of spanning trees in SRB networks, which provides a single path for spanning explorer frames to traverse from a given node in the network to another. Spanning explorer frames have asingle-routebroadcast indicator set in the routing information field. Port identifiers consist of ring numbers and bridge numbers associated with the ports. Thespanning-treealgorithm for SRB does not support Topology Change Notification bridge protocol data unit (BDPU).

Note Although the automaticspanning-treefunction can be configured withsource-routetranslational bridging (SR/TLB), the SRB domain and transparent bridging domain have separate spanning trees. Each Token Ring interface can belong to only one spanning tree. Only one bridge group can run the automaticspanning-treefunction at a time.

Configuring Source-RouteBridgingBC-115

Configure Source-RouteBridging

To create a bridge group that runs an automatic spanning-treefunction compatible with the IBM SRBspanning-treeimplementation, use the following command in global configuration mode:

Command

Purpose

bridge bridge-group protocol ibm

Create a bridge group that runs the

 

automatic spanning-treefunction.

 

 

To enable the automatic spanning-treefunction for a specified group of bridged interfaces, use the following command in interface configuration mode:

Command

Purpose

source-bridgespanningbridge-group

Enable the automatic spanning-tree

 

function on a group of bridged

 

interfaces.

 

 

To assign a path cost for a specified interface, use the following command in interface configuration mode:

Command

Purpose

source-bridgespanningbridge-group path-costpath-cost

Assign a path cost for a specified

 

group of bridged interfaces.

 

 

Note Ports running IEEE and IBM protocols form a spanning tree together on the LAN, but they do not mix in the router itself. Make sure the configurations are correct and that each LAN runs only one protocol.

See the end of this chapter for an example of source-routebridging with the automaticspanning-treefunction enabled.

Limit the Maximum SRB Hops

You can minimize explorer storms if you limit the maximum number of source-routebridge hops. For example, if the largest number of hops in the best route between two end stations is six, it might be appropriate to limit the maximumsource-routebridging hops to six to eliminate unnecessary traffic. This setting affectsspanning-treeexplorers andall-routesexplorers sent from source devices.

To limit the number of SRB hops, use one of the following commands in interface configuration mode:

Command

Purpose

source-bridgemax-hopscount

Control the forwarding or blocking of

 

all-routesexplorer frames received

 

on this interface.

 

 

source-bridgemax-in-hopscount

Control the forwarding or blocking of

 

spanning-treeexplorer frames

 

received on this interface.

 

 

source-bridgemax-out-hopscount

Control the forwarding or blocking of

 

spanning-treeexplorer frames sent

 

from this interface.

 

 

BC-116 Bridging and IBM Networking Configuration Guide

Configure Bridging of Routed Protocols

Configure Bridging of Routed Protocols

Source-routebridges use Media Access Control (MAC) information, specifically the information contained in the RIF, to bridge packets. A RIF contains a series of ring and bridge numbers that represent the possible paths the source node might use to send packets to the destination. Each ring number in the RIF represents a single Token Ring in thesource-routebridged network and is designated by a unique12-bitring number. Each bridge number represents a bridge that is between two Token Rings in the SRB network and is designated by a unique4-bitbridge number. The information in a RIF is derived from explorer packets traversing thesource-routebridged network. Without the RIF information, a packet could not be bridged across asource-routebridged network.

Unlike source-routebridges, Level 3 routers useprotocol-specificinformation (for example, Novell Internetwork Packet Exchange (IPX) or Xerox Network Systems (XNS) headers) rather than MAC information to route datagrams. As a result, the Cisco IOS software default for routed protocols is to not collect RIF information and to not be able to bridge routed protocols. However, if you want the software to bridge routed protocols across asource-routebridged network, the software must be able to collect and use RIF information to bridge packets across asource-routebridged network. You can configure the software to append RIF information to routed protocols so that routed protocols can be bridged.Figure 49 shows a network topology in which you would want to use this feature.

Figure 49 Topology for Bridging Routed Protocols across a Source-RouteBridged

Network

Cisco routed network

Cisco routed network

Source-routebridged

Token Ring network

S2328

To configure the Cisco IOS software to bridge routed protocols, you must perform the task in the first section, and optionally, one or both of the tasks in the other sections as follows:

Enable Use of the RIF

Configure a Static RIF Entry

Configure the RIF Timeout Interval

Enable Use of the RIF

You can configure the Cisco IOS software so that it will append RIF information to the routed protocols. This allows routed protocols to be bridged across a source-routebridged network. The routed protocols that you can bridge are as follows:

Apollo Domain

AppleTalk

ISO Connectionless Network Service (CLNS)

DECnet

IP

IPX

Configuring Source-RouteBridgingBC-117

Configure Bridging of Routed Protocols

VINES

XNS

Enable use of the RIF only on Token Ring interfaces on the router.

To configure the Cisco IOS software to append RIF information, use the following command in interface configuration mode:

Command

Purpose

multiring {protocol-keyword [all-routes| spanning] | all|

Enable collection and use of RIF

other}

information.

 

 

For an example of how to configure the software to bridge routed protocols, see the “SRB and Routing Certain Protocols Example” section later in this chapter.

Configure a Static RIF Entry

If a Token Ring host does not support the use of IEEE 802.2 TEST or XID datagrams as explorer packets, you might need to add static information to the RIF cache of the router.

To configure a static RIF entry, use the following command in global configuration mode:

Command

Purpose

rif mac-addressrif-string{interface-name| ring-group

Enter static source-routeinformation

ring}

into the RIF cache.

 

 

Configure the RIF Timeout Interval

RIF information that can be used to bridge routed protocols is maintained in a cache whose entries are aged.

Note Therif validate enable commands have no effect on remote entries learned over RSRB.

To configure the number of minutes an inactive RIF entry is kept in the cache, use the following commands in global configuration mode:

Step

Command

Purpose

1

rif timeout minutes

Specify the number of minutes an inactive

 

 

RIF entry is kept.

 

 

 

2

rif validate-enable

Enable RIF validation for entries learned on

 

 

an interface (Token Ring or FDDI).

 

 

 

3

rif validate-enable-age

Enable RIF validation on an SRB that is

 

 

malfunctioning.

 

 

 

4

rif validate-enable-route-cache

Enable synchronization of the RIF cache with

 

 

the protocol route cache.

 

 

 

BC-118 Bridging and IBM Networking Configuration Guide

Configure Translation between SRB and Transparent Bridging Environments

Configure Translation between SRB and Transparent Bridging Environments

Source-routetranslational bridging (SR/TLB) is a Cisco IOS software feature that allows you to combine SRB and transparent bridging networks without the need to convert all of your existingsource-routebridges tosource-routetransparent (SRT) nodes. As such, it provides acost-effectiveconnectivity path between Ethernets and Token Rings, for example.

When a router is configured for SR/TLB, the router operates in fast-switchingmode by default, causing packets to be processed in the interrupt handler when the packets first arrive, rather than queuing them for scheduled processing. You can also use theno source-bridge transparent fastswitch command to disablefast-switchedSR/TLB, causing the router to handle packets by process switching. For more information on disablingfast-switchedSR/TLB, refer to the“Disable Fast-Switched SR/TLB” section in this chapter.

Note When you are translationally bridging, you will have to route routed protocols and translationally bridge all others, such aslocal-areatransport (LAT).

Overview of SR/TLB

You can bridge packets between an SRB domain and a transparent bridging domain. Using this feature, a software “bridge” is created between a specified virtual ring group and a transparent bridge group. To the source-routestation, this bridge looks like a standardsource-routebridge. There is a ring number and a bridge number associated with a ring that actually represents the entire transparent bridging domain. To the transparent bridging station, the bridge represents just another port in the bridge group.

When bridging from the SRB (typically, Token Ring) domain to the transparent bridging (typically, Ethernet) domain, the source-routefields of the frames are removed. The RIFs are cached for use by subsequent return traffic.

When bridging from the transparent bridging domain to the SRB domain, the router checks the packet to see if it has a multicast or broadcast destination or a unicast (single host) destination. If it is multicast, the packet is sent as a spanning-treeexplorer. If it is a unicast destination, the router looks up the path to the destination in the RIF cache. If a path is found, it will be used; otherwise, the router will send the packet as aspanning-treeexplorer.

An example of a simple SR/TLB topology is shown in Figure 50.

Configuring Source-RouteBridgingBC-119

Configure Translation between SRB and Transparent Bridging Environments

Figure 50 Example of a Simple SR/TLB Topology

 

 

Transparent

 

 

bridging "ring"

 

 

Transparent

Source-route

Router running

bridging domain

bridged domain

SR/TLB

 

Token

 

 

Ring

 

 

Frames lose RIFs in this direction

Frames gain RIFs in this direction

S1108a

Note TheSpanning-TreeProtocol messages used to prevent loops in the transparent bridging domain arenot passed between the SRB domain and the transparent bridging domain. Therefore, you must not set up multiple paths between the SRB and transparent bridging domains.

The following notes and caveats apply to all uses of SR/TLB:

Multiple paths cannot exist between the source-routebridged domain and the transparent bridged domain. Such paths can lead to data loops in the network, because thespanning-treepackets used to avoid these loops in transparent bridging networks do not traverse the SRB network.

Some devices, notably PS/2s under certain configurations running OS/2 Extended Edition Version 1.3, do not correctly implement the “largest frame” processing on RIFs received from remote source-routebridged hosts. The maximum Ethernet frame size is smaller than that allowed for Token Ring. As such, bridges allowing for communication between Ethernet and Token Ring will tell the Token Ring hosts, through the RIF on frames destined to the Token Ring, that hosts on the Ethernet cannot receive frames larger than a specified maximum, typically 1472 bytes. Some machines ignore thisrun-timelimit specification and send frames larger than the Ethernet can accept. The router and any other Token Ring/Ethernet bridge has no choice but to drop these frames. To allow such hosts to successfully communicate across or to an Ethernet, you must configure their maximum frame sizes manually. For the PS/2, this can be done through Communications Manager.

Any access filters applied on any frames apply to the frames as they appear on the media to which the interface with the access filter applies. This is important because in the most common use of SR/TLB (Ethernet and Token Ring connectivity), the bit ordering of the MAC addresses in the frame is swapped. Refer to the SR/TLB examples in the “SRB Configuration Examples” section of this chapter.

Caution Bridging between dissimilar media presents several problems that can prevent communication from occurring. These problems include bit order translation (or usage of MAC addresses as data), maximum transmission unit (MTU) differences, frame status differences, and multicast address usage. Some or all of these problems might be present in a multimedia bridged LAN and prevent communication from taking place. Because of differences in the way end nodes implement Token Ring, these problems are most prevalent when bridging between Token Rings and Ethernets or between Token Ring and FDDI LANs.

BC-120 Bridging and IBM Networking Configuration Guide

Enable Bridging between Transparent Bridging and SRB

We currently know that problems occur with the following protocols when bridged between Token Ring and other media: Novell IPX, DECnet Phase IV, AppleTalk, VINES, XNS, and IP. Further, problems can occur with the Novell IPX and XNS protocols when bridged between FDDI and other media. We recommend that these protocols be routed whenever possible.

To enable SR/TLB, you must perform the task in the following section:

Enable Bridging between Transparent Bridging and SRB

In addition, you can also perform the tasks in the following sections:

Disable Fast-Switched SR/TLB

Enable Translation Compatibility with IBM 8209 Bridges

Enable Token Ring LLC2-to-Ethernet Conversion

Enable Bridging between Transparent Bridging and SRB

Before enabling bridging, you must have completely configured your router using multiport SRB and transparent bridging. Once you have done this, establish bridging between transparent bridging and source-routebridging by using the following command in global configuration mode:

Command

Purpose

source-bridgetransparentring-group pseudo-ring

Enable bridging between transparent

bridge-numbertb-group[oui]

bridging and SRB.

 

 

Disable Fast-SwitchedSR/TLB

To disable fast-switchedSR/TLB and cause the router to handle packets by process switching, use the following command in global configuration mode:

Command

Purpose

no source-bridgetransparentring-group fastswitch

Disable fast-switchedSR/TLB.

 

 

Enable Translation Compatibility with IBM 8209 Bridges

To transfer data between IBM 8209 Ethernet/Token Ring bridges and routers running the SR/TLB software (to create a Token Ring backbone to connect Ethernets), use the following command on each Token Ring interface in interface configuration mode:

Command

Purpose

ethernet-transit-oui[90-compatible| standard| cisco]

Move data between IBM 8209

 

Ethernet/Token Ring bridges and

 

routers running translational bridging

 

software.

 

 

Configuring Source-RouteBridgingBC-121