Configuring Token Ring and Ethernet VLANs on the Catalyst 5000 using an RSM

Introduction

This document discusses how to configure Token Ring switching on the Catalyst 5000 and the Route Switch Module (RSM). In particular, this document focuses on the configuration of the Catalyst 5000 with the RSM to route IP in a source-route bridged environment, and the steps involved. It also gives an example configuration for communication between an Ethernet VLAN and a Token Ring VLAN through the RSM. This document also discusses some of the most frequently used show commands.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

• Token Ring Switching concepts, including Token Ring Bridge Relay Function (TrBRF) and Token Ring Concentrator Relay Function (TrCRF).

• How to configure and manage Cisco routers and switches.

Components Used

The information in this document is based on these software and hardware versions:

• Catalyst 5505 with Supervisor Engine III Software version 4.5(6), with these installed:

  • Route Switch Module with Cisco IOS® Software Release 12.1(2) with IBM Feature Set

  • Ethernet Blade with software version 4.5(6)

  • Token Ring Blade with software version 3.3(2)

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Background Theory

Unlike Ethernet VLANs, where one VLAN effectively represents one physical Ethernet segment (for example, a broadcast domain), Token Ring switching uses multiple VLANs per broadcast domain. The central concept is the Token Ring Bridge Relay Function (TrBRF) VLAN. This is a VLAN which represents the bridging functionality in a Token Ring network. Under this TrBRF, or bridge, you configure one or more Token Ring Concentrator Relay Function (TrCRF) VLANs. These are analogous to the physical rings in a Token Ring network. As part of the definition, each must be assigned a unique ring number.

End devices on different TrCRFs can communicate with each other without any external bridge or router via the bridging functionality in the TrBRF. One switch may be configured with more than one TrBRF VLAN, each with its associated TrCRF VLANs. However, for communication between the TrBRFs, an external device such as a router is needed.

The TrBRF VLAN can be configured in two ways: either as a Transparent Bridge, or as a Source Route Bridge. Because typical Token Ring switches are installed in IBM shops which already use Source Route Bridging (SRB), the most common configuration of the TrBRF is as a Source Route Bridge.

Token Ring VLANs, like Ethernet VLANs, need to run a spanning tree algorithm to avoid loops. However, unlike Ethernet VLANs, they need to run two instances of this, one at the TrBRF level and one at the TrCRF level.

If the TrBRF is functioning as a Transparent Bridge (mode srt when you are setting up the dependent TrCRFs), then it must be configured to run IEEE as the Spanning Tree Protocol at the TrBRF level (stp ieee).

If the TrBRF is functioning as a Source Route Bridge (mode srb when setting up the dependent TrCRFs), then it must be configured to run IBM as the Spanning Tree Protocol at the TrBRF level (stp ibm).

The Spanning Tree Protocol that runs at the TrCRF level is automatically chosen based on the bridging mode. If the bridging mode is SRB (for example, the TrBRF is running the IBM Spanning Tree Protocol), then the IEEE Spanning Tree Protocol is run at the TrCRF level. If the bridging mode is Transparent Bridging (the TrBRF is already running the IEEE Spanning Tree Protocol, for instance), then the spanning tree protocol run at the TrCRF level is CISCO.

For more information on the concept of TrBRF and TrCRF, refer to Token Ring Switching Concepts.

Configure

In this section, you are presented with the information to configure the features described in this document.

Note: Use the Command Lookup Tool (registered customers only) to find more information on the commands used in this document.

Before you can configure any Token Ring VLANs, all Token Ring switches in the domain must be running VLAN Trunking Protocol (VTP) V2. In order to avoid a disruption of the existing VTP domain, you should configure newly added switches as Transparent or Client mode with this command:

set vtp domain cisco mode transparent V2 enable

For more information on VTP, refer to Configuring VTP. The default mode is server.

Next, set up the TrBRF VLAN or VLANs on the switch. In this example, there are two separate TrBRFs set up as Source Route Bridges, as this is the most common type of configuration.

1. Create the TrBRF VLANs on the switch.

   This is the parent for the TrCRF VLANs which has ports with connected end devices assigned to it.

   Note: Because you are doing Source Route Bridging, the Spanning Tree Protocol is set to ibm.

   set vlan 100 type trbrf name test_brf bridge 0xf stp ibm
   set vlan 200  type trbrf name test_brf2  bridge 0xf stp ibm
   

2. Create the TrCRF VLANs.

   Note: The mode is set to SRB and the ring number can be entered in hexadecimal or decimal notation, as shown in the next example. However, when you display the configurations, the switch displays them in hexadecimal.

   set vlan 101 type trcrf name test_crf101  ring 0x64  parent 100 mode srb
   
   !--- All rings in hexadecimal.
   
   set vlan 102 type trcrf name test_crf102  ring 0x65 parent 100 mode srb
   set vlan 103 type trcrf name test_crf103 ring 0x66 parent 100 mode srb
   
   set vlan 201 type trcrf name test_crf201 decring 201 parent 200 mode srb
   
   !--- All rings in decimal.
   
   set vlan 202 type trcrf name test_crf202 decring 202 parent 200 mode srb
   set vlan 203 type trcrf name test_crf203 decring 203 parent 200 mode srb
   

3. Assign the VLANs to the ports intended in the switch network.

   Assign the ports to the CRF VLANs in the same way that Ethernet ports are assigned.

   For example, here you assign ports 8/1-4 to VLAN 101, which is ring number 100 (0x64). Because the default VLAN for all Token Ring ports is 1003—in the same way that VLAN 1 is the default for all Ethernet ports—VLAN 1003 is also modified.

   ptera-sup (enable) set vlan 101 8/1-4
   
   VLAN 101 modified.
   VLAN 1003 modified.
   VLAN  Mod/Ports
   ---- -----------------------
   101   8/1-4
   
   ptera-sup (enable) set vlan 201 8/5-8
   
   VLAN 201 modified.
   VLAN 210 modified.
   VLAN  Mod/Ports
   ---- -----------------------
   201   5/1
         8/5-8

   Once you have assigned all the required Token Ring ports to TrCRF VLANs, you have finished the configuration of the switch. Devices in TrCRFs under the same VLAN are now able to source route bridge between them.

For IP connectivity, because this is a bridged environment, all end devices must be part of the same IP network. However, because the TrBRF is functioning as a source route bridge, routers connected to different TrCRFs require the multi-ring option, to cache and use the Routing Information Field (RIF).

For example, an external router connected to TrCRF 101 would have its Token Ring interface configured similar to this:

source-bridge ring-group 2000
!
interface token-ring 0
 ip address 1.1.1.10 255.255.255.0
 multiring all
 source-bridge 100 1 2000

!--- The ring number is 100, to match CRF 101 ring number; !--- and 2000 is the virtual ring number of the router.

 source-bridge spanning

Configuring Token Ring with RSM for SRB and Multiring for IP

If you are routing IP in a source-route bridged network, you need to add multi-ring to your configuration as well as configure source-route bridging. This is because, with the RSM, you are extending the bridge from the switch to the RSM, and you must create a pseudo ring that the multi-ring code appends to the RIF. You create this pseudo ring when you create a TrCRF under the parent TrBRF that is assigned in the RSM under the multi-ring code.

Because you also need to configure source-route bridging for the RSM, you must tie the interface VLAN to the virtual ring of the RSM. This is done when you create a TrCRF under each TrBRF with a ring number that matches that of the virtual ring in the RSM. In fact, you can use the same TrCRF for both multi-ring and source route bridging purposes, provided they have the same ring number. See the next diagram:

In this example, you are going to set up the RSM as virtual ring 1000 with the global source-bridge ring-group 1000 command.

1. Set up the corresponding pseudo-TrCRFs on the switch, one for each TrBRF, with these commands:

   set vlan 104 type trcrf name test_crf104 decring 1000  parent 100 mode srb
   set vlan 204 type trcrf name test_crf204 decring 1000  parent 200 mode srb
   

   Note: The ring numbers for the above TrCRFs have to match the virtual ring in the RSM, 1000. Also, no ports are assigned to the pseudo-TrCRFs. The physical ports are assigned to TrCRF 101 and 201, as shown in the example in Step 3 of the main Configure section of this document.

2. Add an interface vlan command in the RSM for each TrBRF configured on the switch:

   interface vlan100 type trbrf
   interface vlan200 type trbrf
   

3. Add the multi-ring and source route bridging commands to the VLAN interfaces.

   These tell the router what TrCRF VLAN has been assigned to map onto the virtual ring in the router. In this document example, it is VLANs 104 and 204, both with a ring number of 1000 to match the ring-group in the router.

   You also need to add IP addresses to route IP traffic, so that you end up with this configuration:

   source-bridge ring-group 1000
   !
   interface vlan100 type trbrf
    ip address 1.1.1.1 255.255.255.0
    multiring trcrf-vlan 104 ring 1000
    multiring all
    source-bridge trcrf-vlan 104 ring-group 1000
    source-bridge spanning
   !
   interface Vlan200 type trbrf
    ip address 1.1.2.1 255.255.255.0
    multiring trcrf-vlan 204 ring 1000
    multiring all
    source-bridge trcrf-vlan 204 ring-group 1000
    source-bridge spanning
   !
   

   Note: IP protocol configurations are not shown in this example, for simplicity.

Communicating Between Ethernet and Token Ring VLANs on the Same Switch

You can configure Token Ring and Ethernet VLANs on the same switch, but you can only send traffic between them with an RSM or an external router.

If you have already configured the switch and the RSM as described earlier in this document, you could add an Ethernet VLAN and configure source bridge translational on the RSM, to bridge traffic between the two media:

1. Set up the Ethernet VLAN and assign ports to it with the set vlan command:

   ptera-sup (enable) set vlan 500 3/1-5
   
   Vlan 500 configuration successful
   VLAN 500 modified.
   VLAN 1 modified.
   VLAN  Mod/Ports
   ---- -----------------------
   500   3/1-5

2. Set up the VLAN interface on the RSM and put it in a transparent bridge-group:

   interface vlan 500 
   bridge-group 1 
   
   bridge 1 protocol ieee 
   

3. Configure source bridge translational with the source-bridge transparent ring-group pseudo-ring bridge-number tb-group command where:

   • ring-group is the source-bridge ring-group virtual ring that is configured on the RSM. In this case, it is 1000.

   • pseudo-ring is the ring number that is going to be assigned to this transparent bridging domain. You can choose any number, but it should be unique in the same way that real ring numbers should be unique within a source-route bridged network. In the previous example, the ring number is 3000.

   • bridge-number is the bridge number that is used to form the RIF in frames that are coming from the transparent bridge group and are being sent to the source route bridged network. In this case, you are using 1.

   • tb-group is the transparent bridge group number. In this case, it is 1.

   source-bridge transparent 1000 3000 1 1
   source-bridge ring-group 1000
       !
   interface vlan100 type trbrf
        ip address 1.1.1.1 255.255.255.0
        multiring trcrf-vlan 104 ring 1000
        multiring all
        source-bridge trcrf-vlan 104 ring-group 1000
        source-bridge spanning
       !
   interface Vlan200 type trbrf
        ip address 1.1.2.1 255.255.255.0
        multiring trcrf-vlan 204 ring 1000
        multiring all
        source-bridge trcrf-vlan 204 ring-group 1000
        source-bridge spanning
       !
   interface vlan 500
     ip address 1.1.3.1 255.255.255.0
     bridge-group 1
   
   bridge 1 protocol ieee
   

   Note: In this scenario, IP is being routed, not bridged.

Verify

Use this section to confirm that your configuration works properly.

The Output Interpreter Tool (registered customers only) (OIT) supports certain show commands. Use the OIT to view an analysis of show command output.

show vlan—On the switch, you can check which VLANs are configured, the bridging mode, and the spanning tree.

ptera-sup (enable) show vlan

VLAN Name                             Status    IfIndex Mod/Ports   VLANs
---- -------------------------------- --------- ------- ------------------------
1    default                          active    3       3/6-24
                                                        6/1-24
                                                        10/1-12
100  test_brf                         active    8       8           101, 102, 103, 104
                                                        105
101  test_crf101                      active    10      8/1-4
102  test_crf102                      active    11
103  test_crf103                      active    12
104  test_crf104                      active    13
105  test_crf105                      active    14
200  test_brf2                        active    9       9           201, 202, 203, 204
                                                        205
201  test_crf201                      active    15      8/5-8
202  test_crf202                      active    16
203  test_crf203                      active    17
204  test_crf204                      active    18
205  test_crf205                      active    19
210  VLAN0210                         active    98
500  VLAN0500                         active    20      3/1-5
1002 fddi-default                     active    4
1003 trcrf-default                    active    7       8/9-16
1004 fddinet-default                  active    5
1005 trbrf-default                    active    6       6           1003

VLAN Type  SAID       MTU   Parent RingNo BrdgNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ ------ ---- -------- ------ ------
1    enet  100001     1500  -      -      -      -    -        0      0
100  trbrf 100100     4472  -      -      0xf    ibm  -        0      0
101  trcrf 100101     4472  100    0x64   -      -    srb      0      0
102  trcrf 100102     4472  100    0x65   -      -    srb      0      0
103  trcrf 100103     4472  100    0x66   -      -    srb      0      0
104  trcrf 100104     4472  100    0x3e8  -      -    srb      0      0
105  trcrf 100105     4472  100    0x7d0  -      -    srb      0      0
200  trbrf 100200     4472  -      -      0xf    ibm  -        0      0
201  trcrf 100201     4472  200    0xc9   -      -    srb      0      0  
 !--- All ring numbers are displayed in hexadecimal.

202  trcrf 100202     4472  200    0xca   -      -    srb      0      0
203  trcrf 100203     4472  200    0xcb   -      -    srb      0      0
204  trcrf 100204     4472  200    0x3e8  -      -    srb      0      0
205  trcrf 100205     4472  200    0x7d0  -      -    srb      0      0
210  enet  100210     1500  -      -      -      -    -        0      0
500  enet  100500     1500  -      -      -      -    -        0      0
1002 fddi  101002     1500  -      -      -      -    -        0      0
1003 trcrf 101003     4472  1005   0xccc  -      -    srb      0      0
1004 fdnet 101004     1500  -      -      0x0    ieee -        0      0
1005 trbrf 101005     4472  -      -      0xf    ibm  -        0      0

VLAN DynCreated
---- ----------
1    static
100  static
101  static
102  static
103  static
104  static
105  static
200  static
201  static
202  static
203  static
204  static
205  static
210  static
500  static
1002 static
1003 static
1004 static
1005 static

VLAN AREHops STEHops Backup CRF 1q VLAN
---- ------- ------- ---------- -------
101  7       7       off
102  7       7       off
103  7       7       off
104  7       7       off
105  7       7       off
201  7       7       off
202  7       7       off
203  7       7       off
204  7       7       off
205  7       7       off
1003 7       7       off
ptera-sup (enable)

show spantree TrBRF vlan_number —Displays important information, such as which ports are being connected and forwarding, and displays the spanning tree mode running at the TrBRF level.

ptera-sup (enable) show spantree 100

VLAN 100
Spanning tree enabled
Spanning tree type          ibm
Designated Root             00-10-1f-29-f9-63
Designated Root Priority    32768
Designated Root Cost        0
Designated Root Port        1/0
Root Max Age   10 sec    Hello Time 2  sec   Forward Delay 4  sec

Bridge ID MAC ADDR          00-10-1f-29-f9-63
Bridge ID Priority          32768
Bridge Max Age 10 sec    Hello Time 2  sec   Forward Delay 4  sec

Port,Vlan                Vlan Port-State    Cost  Priority Portfast   Channel_id
------------------------ ---- ------------- ----- -------- ---------- ----------
 5/1                     100  forwarding        5        4 disabled   0
 101                     100  inactive         62        4 disabled
 102                     100  inactive         62        4 disabled
 103                     100  inactive         62        4 disabled
 104                     100  inactive         62        4 disabled
 105                     100  inactive         62        4 disabled
* = portstate set by user configuration.

Note: In that output, you see port 5/1 listed under TrBRF VLAN 100. This is because you have an RSM in slot 5 and because an ISL trunk is used to extend the bridge from the switch to the RSM automatically. For more information on Token Ring ISL, refer to TR-ISL Trunking Between Cisco Catalyst 5000 and 3900 Switches and Routers.

show spantree TrCRF vlan_number —Displays important information, such as which ports are being connected and forwarding, and displays the spanning tree mode running at the TrCRF level.

ptera-sup (enable) show spantree 101

VLAN 101
Spanning tree enabled
Spanning tree type          ieee
Designated Root             00-10-1f-29-f9-64
Designated Root Priority    32768
Designated Root Cost        0
Designated Root Port        1/0
Root Max Age   10 sec    Hello Time 2  sec   Forward Delay 4  sec

Bridge ID MAC ADDR          00-10-1f-29-f9-64
Bridge ID Priority          32768
Bridge Max Age 10 sec    Hello Time 2  sec   Forward Delay 4  sec

Port                     Vlan Port-State    Cost  Priority Portfast   Channel_id
------------------------ ---- ------------- ----- -------- ---------- ----------
 5/1                     101  forwarding*       5       32 disabled   0
 8/1                     101  not-connected   250       32 disabled   0
 8/2                     101  not-connected   250       32 disabled   0
 8/3                     101  not-connected   250       32 disabled   0
 8/4                     101  not-connected   250       32 disabled   0
* = portstate set by user configuration or set by vlan 100 spanning tree.
ptera-sup (enable)

show port—Verifies the existence of the ISL trunk.

ptera-sup (enable) show port 5/1

Port  Name               Status     Vlan       Level  Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
 5/1                     connected  trunk      normal   half   400 Route Switch

Port   Trap      IfIndex
-----  --------  -------
 5/1   disabled  81

Last-Time-Cleared
--------------------------
Sat Jun 29 2002, 03:15:59
ptera-sup (enable)

show trunk—Displays which ports are forwarding and which ones are inactive, and displays the spanning tree mode at the TrBRF level.

ptera-sup (enable) show trunk

Port      Mode         Encapsulation  Status        Native vlan
--------  -----------  -------------  ------------  -----------
 5/1      on           isl            trunking      1
 7/1-2    on           lane           trunking      1

Port      Vlans allowed on trunk
--------  ---------------------------------------------------------------------
 5/1      1-1005
 7/1-2    1-1005

Port      Vlans allowed and active in management domain 
--------  ---------------------------------------------------------------------
 5/1
 7/1-2    1003

Port      Vlans in spanning tree forwarding state and not pruned
--------  ---------------------------------------------------------------------
 5/1      100-105,200-205
 7/1-2    1003
ptera-sup (enable)

show interface—Displays the VLAN configurations on the RSM in the same way as physical interfaces on a router.

ptera-rsm# show interface

Vlan100 is up, line protocol is up
  Hardware is Cat5k Virtual Token Ring, address is 0009.fa18.3800 (bia0009.fa18.3800)
  Internet address is 1.1.1.1/24
  MTU 4464 bytes, BW 16000 Kbit, DLY 630 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation SNAP, loopback not set
  ARP type: SNAP, ARP Timeout 04:00:00
  Ring speed: 16 Mbps
  Duplex: half
  Mode: Classic token ring station
  Source bridging enabled, srn 0 bn 15 trn 1000 (ring group)
    spanning explorer enabled
  Group Address: 0x00000000, Functional Address: 0x08000100
  Ethernet Transit OUI: 0x000000
  Last input 00:00:01, output 00:00:55, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue :0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     390 packets input, 21840 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     25 packets output, 6159 bytes, 0 underruns
     0 output errors, 1 interface resets
     0 output buffer failures, 0 output buffers swapped out
     3 transitions
Vlan200 is up, line protocol is up
Hardware is Cat5k Virtual Token Ring, address is 0009.fa18.3800 (bia0009.fa18.3800)
  Internet address is 1.1.2.1/24
  MTU 4464 bytes, BW 16000 Kbit, DLY 630 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation SNAP, loopback not set
  ARP type: SNAP, ARP Timeout 04:00:00
  Ring speed: 16 Mbps
  Duplex: half
  Mode: Classic token ring station
  Source bridging enabled, srn 0 bn 15 trn 1000 (ring group)
    spanning explorer enabled
  Group Address: 0x00000000, Functional Address: 0x08000100
  Ethernet Transit OUI: 0x000000
  Last input 00:00:00, output 00:08:43, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue :0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     381 packets input, 21336 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     9 packets output, 783 bytes, 0 underruns
     0 output errors, 1 interface resets
     0 output buffer failures, 0 output buffers swapped out
     3 transitions
ptera-rsm#

show spanning-tree—Displays information about which Spanning Tree Protocol is running on the RSM.

ptera-rsm# show spanning-tree

 Bridge group 1 is executing the IEEE compatible Spanning Tree protocol
  Bridge Identifier has priority 32768, address 0090.5f18.1c00
  Configured hello time 2, max age 20, forward delay 15
  We are the root of the spanning tree
  Port Number size is 12
  Topology change flag not set, detected flag not set
  Times:  hold 1, topology change 35, notification 2
          hello 2, max age 20, forward delay 15
  Timers: hello 0, topology change 0, notification 0
  bridge aging time 300

Port 12 (Vlan500) of Bridge group 1 is down
   Port path cost 19, Port priority 128
   Designated root has priority 32768, address 0090.5f18.1c00
   Designated bridge has priority 32768, address 0090.5f18.1c00
   Designated port is 12, path cost 0
   Timers: message age 0, forward delay 0, hold 0
   BPDU: sent 0, received 0

Port 13 (RingGroup1000) of Bridge group 1 is forwarding
   Port path cost 10, Port priority 128
   Designated root has priority 32768, address 0090.5f18.1c00
   Designated bridge has priority 32768, address 0090.5f18.1c00
   Designated port is 13, path cost 0
   Timers: message age 0, forward delay 0, hold 0
   BPDU: sent 0, received 0

ptera-rsm#

Troubleshoot

There is currently no specific troubleshooting information available for this configuration.

Related Information

• Token Ring Route Switch Module
• TR-ISL Trunking Between Cisco Catalyst 5000 and 3900 Switches and Routers
• Token Ring Support Page
• IBM Technology Support
• Product Support
• Technical Support & Documentation - Cisco Systems