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This document describes the Token Ring LAN Emulation (LANE) on the Catalyst 5000 series ATM module feature in Cisco IOS Release 12.0(7)T and contains the following sections:
LANE bridges LAN traffic across an Asychronous Transfer Mode (ATM) network. The Catalyst 5000 Series Token Ring LANE feature emulates an IEEE 802.5 Token Ring LAN using ATM technology. LANE is transparent to upper-layer protocols and applications. No changes are required to existing upper-layer protocols and applications. With Token Ring LANE, Token Ring packets are encapsulated in the appropriate ATM cells and sent across the ATM network. When the packets reach the other side of the ATM network, they are de-encapsulated.
This section contains the following information:
ATM is a cell-switching and multiplexing technology that combines the benefits of circuit switching (constant transmission delay and guaranteed capacity) with those of packet switching (flexibility and efficiency for intermittent traffic). Like X.25 and Frame Relay, ATM defines the interface between the user equipment (such as workstations and routers) and the network (referred to as the User-Network Interface [UNI]).
Token Ring LANE allows Token Ring LAN users to take advantage of ATM's benefits without modifying end-station hardware or software. ATM uses connection-oriented service with point-to-point signaling or multicast signaling between source and destination devices. However, Token Ring LANs use connectionless service. Messages are broadcast to all devices on the network. With Token Ring LANE, routers and switches emulate the connectionless service of a Token Ring LAN for the end stations.
By using Token Ring LANE, you can scale your networks to larger sizes while preserving your investment in LAN technology.
LANE defines emulated LANs (ELANs). An ELAN consists of the following components:
The Token Ring LANE on the Catalyst 5000 series ATM module feature supports the following networking features:
The Cisco implementation of LAN emulation over IEEE 802.5 uses existing terminology and configuration options for Token Rings and provides for the IEEE 802.5 transport of Token Ring frames across an ATM switching fabric.
Before you implement Token Ring LANE, be aware of the following restrictions:
 | Caution While VLAN Trunking Protocol (VTP) Version 2 must be enabled on a Catalyst 5000 for Token Ring to function, do not use VTP to distribute VLAN configuration information between the switches. Configure the switches to operate in VTP transparent mode and manually configure the VLANs on each switch. |
lane config-atm address atm-address template
The Token Ring LANE on the Catalyst 5000 ATM module feature is related to the existing Ethernet LANE feature which is documented in the Cisco IOS Switching Services Configuration Guide.
The following document contains Ethernet LANE configuration information:
The following documents are available for the Catalyst 5000 family switch:
For information on how to install and configure the Catalyst 5000 family ATM modules, refer to the Catalyst 5000 Series Module Installation Guide.
For information on how to access the ATM module command-line interface (CLI) and customize the configuration from the terminal and from nonvolatile RAM (NVRAM), refer to the following publications:
For quick software configuration procedures for the Catalyst 5000 family switches, refer to the Quick Software Configuration Guide for your switch. For detailed software configuration information and procedures, refer to the Software Configuration Guide for your switch.
The Token Ring LANE feature is supported on the ATM module in the Catalyst 5000 platform. This feature is supported on the following Catalyst 5000 series ATM modules:
Support for the Token Ring LANE feature was first introduced in the Cisco IOS 12.0(7)T.
No new or modified standards are supported by this feature.
For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
No new or modifed RFCs are supported by this feature.
Token Ring LANE requires that the Catalyst 5000 series switch contain one of the following ATM modules running ATM software Release 4.9b or later:
These ATM modules provide an ATM network interface for the Catalyst 5000 series switch. Network interfaces reside on modular interface processors, which provide a direct connection between the high-speed synergy backplane and the external networks. The maximum number of ATM modules that the switch supports depends on the bandwidth configured.
The Catalyst 5000 series Token Ring LANE software also requires the Catalyst 5000 series supervisor engine software Release 4.3(1a) or later and one of the following switches:
To configure Token Ring LANE, complete the tasks in the following sections:
Before configuring Token Ring LANE, you must first open a session with the ATM module in the Catalyst 5000 series switch by entering the session command from the supervisor Console> prompt. After opening the session, you see the ATM> prompt. You only have direct access to the ATM module with which you have established a session.
Use the session mod_num command to open a session to the ATM module from the Catalyst 5000 family switch in which the module is installed.
This example shows how to session to an ATM module installed in slot 5 of the Catalyst 5000 switch:
Console> (enable) session 5 Trying ATM-5... Connected to ATM-5. Escape character is '^]'. ATM>
After opening the session, you see the ATM> prompt. You then have direct access only to the ATM module with which you have established a session.
To configure the ATM module, you must use the ATM configuration mode in the Cisco IOS software. To enter global configuration mode, enter the configure EXEC command at the privileged EXEC prompt (ATM#). You see the following message, which asks you to specify the terminal, the NVRAM, or a file stored on a network server as the source of configuration commands:
Configuring from terminal, memory, or network [terminal]?
If you specify terminal, the run-time configuration is used. You can then save the run-time configuration into the NVRAM. If you specify memory, the run-time configuration is updated from the NVRAM. If you specify network, the run-time configuration is updated from a file in a server on the network.
The ATM module accepts one configuration command per line. You can enter as many configuration commands as you want.
You can add comments to a configuration file describing the commands you have entered. Precede a comment with an exclamation point (!) or pound sign (#). Comments are not stored in NVRAM or in the active copy of the configuration file. In other words, comments do not appear when you list the active configuration with the write terminal EXEC command or list the configuration in NVRAM with the show configuration EXEC command. Comments are stripped out of the configuration file when it is loaded to the ATM module.
To configure the ATM module from the terminal, complete the following steps beginning in privileged EXEC mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM#configure terminal | Selects the terminal option and enters global configuration mode. | ||
| Refer to the appropriate tasks in this document for more information about specific commands. | Enter the necessary configuration commands. | ||
| ATM(config-if)# | Exits global configuration mode. | ||
| ATM(config)# | Saves the configuration file modifications to NVRAM. |
In the following example, the ATM module is configured from the terminal. The interface atm 0 command designates that the ATM interface 0 is to be configured. The lane client tokenring command links TrCRF 10 to the ELAN named trcrf-10. The Ctrl-Z command quits configuration mode. The write memory command loads the configuration changes into NVRAM on the ATM module.
ATM# configure terminal ATM (config)# interface atm 0 ATM (config-subif)# lane client tokenring 10 trcrf-10 ATM (config-subif)# Ctrl-Z ATM# write memory
NVRAM stores the current configuration information in text format as configuration commands, recording only nondefault settings. The ATM module software performs a memory checksum to guard against corrupted data.
As part of its startup sequence, the ATM module startup software always checks for configuration information in NVRAM. If NVRAM holds valid configuration commands, the ATM module executes the commands automatically at startup. If the ATM module detects a problem with its NVRAM or the configuration it contains, the module goes into default configuration. Problems can include a bad checksum for the information in NVRAM or the absence of critical configuration information.
Configure the ATM module from NVRAM by reexecuting the configuration commands in privileged EXEC mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#configure memory | Configures the ATM module from NVRAM. |
Before you begin to configure Token Ring LANE, you must decide whether you want to set up one or multiple ELANs. If you set up multiple ELANs, you must also decide where the servers and LECs will be located, and whether to restrict the clients that can belong to each ELAN. Bridged ELANs are configured just like any other LAN, in terms of commands and outputs. Once you have made those decisions, you can configure Token Ring LANE.
Before implementing Token Ring LANE, it might help you to begin by drawing up a plan and a worksheet for your own LANE scenario, showing the following information and leaving space to note the ATM address of each LANE component on each subinterface for each participating switch:
Table 1 shows the default LANE configuration.
| Feature | Default Value |
|---|---|
LANE components
| No LECS database is configured. No LES/BUS is configured. No LECs are configured. |
PVCs | ILMI and signaling PVCs are set up. |
Preferred PHY (Dual PHY modules only) | PHY A |
Output throttling | Disabled |
ILMI keepalives | Disabled |
UNI version | Autonegotiate (reverts to UNI 3.0 if autonegotiation fails) |
VTP | Disabled |
Before you configure LANE components on a Catalyst 5000 series switch ATM module, you must configure the Cisco LightStream 1010 switch with the ATM address prefix to be used by all LANE components in the switch cloud.
To set the ATM address prefix, complete the following tasks on the Cisco LightStream 1010 switch, beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Switch(config)#atm address {atm_address |
prefix...}
| Sets the local node ID (prefix of the ATM address). | ||
| Switch(config)#exit | Exits global configuration mode. | ||
| Switch#copy running-config startup-config | Saves the configuration values permanently. |
To display the current prefix on the Cisco LightStream 1010 switch, use the show network command.
You must set up the signaling PVC and the PVC that will communicate with the ILMI on the major ATM interface of any Catalyst 5000 series switch that participates in LANE. Complete this task only once for a major interface. You do not need to repeat this task on the same interface even though you might configure LESs and clients on several of its subinterfaces.
To set up these PVCs, complete the following tasks, beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#interface atm slot/port | Specifies the major ATM interface and enters interface configuration mode. | ||
| ATM(config)#atm pvc vcd vpi vci qsaal | Establishes the signaling PVC that sets up and tears down switched virtual circuits (SVCs); the vpi and vci values are usually set to 0 and 5, respectively. The vcd is the virtual channel descriptor. | ||
| ATM(config)#atm pvc vcd vpi vci ilmi | Sets up a PVC to communicate with the ILMI; the vpi and vci values are usually set to 0 and 16, respectively. |
You can display the LANE default addresses to make configuration easier. Complete this task for each Catalyst 5000 series switch ATM interface that participates in LANE. The show lane default-atm-address command displays default addresses for all ATM interfaces present on the switch. Write down the displayed addresses on your LANE worksheet.
To display the default LANE addresses, complete the following task beginning in global configuration mode:
| Command | Purpose |
|---|---|
ATM#show lane default-atm-addresses [interface atm number[.subinterface-number]] | Displays the LANE default addresses. |
You must enter the LECS ATM address into each ATM switch (such as a LightStream 1010 ATM switch) connected to an ATM module in your LANE network and save the address permanently so that the value will not be lost when the switch is reset or powered off. Programming the LECS addresses allows the LESs and LECs to determine the LECS addresses dynamically through ILMI.
To enter a LECS ATM address into a LightStream 1010 switch and save it there permanently, complete the following tasks on the LightStream 1010 switch, beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Switch(config)#atm lecs-address-default address1 [address2...] | Specifies the LECS's ATM address for the entire switch. Use the addresses from your LANE worksheet and specify the full 40-digit ATM address. | ||
| Router(config)#exit | Exits global configuration mode. | ||
| Switch#copy running-config startup-config | Saves the configuration value permanently. |
The LECS database contains LANE configuration information, including ELAN name-to-LES/BUS ATM address mappings, LEC address-to-ELAN name mappings, and the name of the default ELAN, if specified. You must configure at least one LECS database in the LANE network.
When configuring the LECS Database, remember the following:
When setting up the LECS database remember that the following are requirements when configuring LECs:
To set up the database, complete the tasks in the following sections as appropriate for your ELAN plan and scenario:
When you configure a Catalyst 5000 series switch ATM module as the LECS for one default ELAN, you need to provide the following information:
In addition, you indicate that the LECS's ATM address is to be computed automatically.
The default ELAN cannot be a restricted-membership ELAN. You do not need to specify the ATM or MAC addresses of the LECs for the default ELAN.
On the Dual PHY ATM modules, you must configure redundant LES/BUS/LECS, one for each PHY.
When you configure a database with only a default unrestricted ELAN, you do not have to specify where the LECs are located. That is, when you set up the LECS's database for a single default ELAN, you do not have to provide any database entries that link the ATM addresses of any clients with the ELAN name. All of the clients are automatically assigned to a default ELAN.
To set up the LECS for a default ELAN, complete the following tasks beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#lane database database-name | Enters database configuration mode for the LANE database that you specify. | ||
| ATM(lane-config-database)#name elan-name server-atm-address atm-address [index n] | Binds the name of the ELAN to the ATM address of the LES in the configuration database. The index determines the priority. The highest priority is 0. Enter the ATM address of the server for the specified ELAN, as noted in your LANE worksheet and obtained in the "Displaying LANE Default Addresses" section. You can have any number of servers per ELAN for fault tolerance. Priority is determined by entry order. The first entry has the highest priority unless you override it with the index number. | ||
| ATM(lane-config-database)#name elan-name local-seg-id segment-number | Assigns a segment number to the emulated Token Ring LAN in the configuration database. The segment number you specify for local-seg-id must remain the same for each entry you add and it must also be identical to the ring number of the TrCRF. The set vlan command assumes that any ring number you enter is in hexadecimal. The name elan-name local-seg-id segment-number command assumes that any value you enter for the local-seg-id is in decimal unless you enter it explicitly in hexadecimal. | ||
| ATM(lane-config-database)#default-name elan-name | Provides a default name for the ELAN in the configuration database. If you are setting up only a default ELAN, the elan-name value in Step 2 and Step 3 is the same as the default ELAN name you provide in Step 4. | ||
| ATM(lane-config-database)#exit | Exits from database configuration mode and returns to global configuration mode. |
When you configure unrestricted-membership ELANs in the LECS database, you create database entries that link the name of each ELAN to the ATM address of its LES/BUS.
However, you may choose not to specify where the LECs are located. That is, when you set up the LECS's database, you do not have to provide any database entries that link the ATM addresses or MAC addresses of any clients with the ELAN name. The LECS assigns the clients to the ELANs specified in the client's configurations.
To configure unrestricted-membership ELANs in the LECS database, perform the following tasks beginning in global configuration mode:
When you configure restricted-membership ELANs in the LECS database, you create database entries that link the name of each ELAN to the ATM address of its LES/BUS.
Unlike unrestricted-membership, you must also specify where the LECs are located. That is, for each restricted-membership ELAN, you provide a database entry that explicitly links the ATM address or MAC address of each client of that ELAN with the name of that ELAN.
Those client database entries specify which clients are allowed to join the ELAN. When a client requests to join an ELAN, the LECS consults its database and then assigns the client to the ELAN specified in the LECS's database.
When clients for the same restricted-membership ELAN are located in multiple switch ATM interfaces, each client's ATM address or MAC address must be linked explicitly with the name of the ELAN. As a result, you must configure as many client entries as you have clients for ELANs in all the switch ATM interfaces. Each client will have a different ATM address in the database entries.
To configure restricted-membership ELANs in the LECS database, perform the following tasks beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#lane database database-name | Enters database configuration mode for the LANE database that you specify. | ||
| ATM(lane-config-database)#name elan-name1 server-atm-address atm-address restricted [index n] | Binds the name of the first ELAN to the ATM address of the LES/BUS for that ELAN in the configuration database. If you are configuring SSRP, repeat this step with the same ELAN name but with different server ATM addresses for each additional server for the same ELAN. The index determines the priority. The highest priority is 0. | ||
| ATM(lane-config-database)# | Binds the name of the second ELAN to the ATM address of the LES/BUS in the configuration database. The index determines the priority. The highest priority is 0. Repeat this step, providing a different name and a different ATM address, for each additional ELAN. | ||
| ATM(lane-config-database)# | Assigns a segment number to the first emulated Token Ring LAN in the configuration database. The segment number you specify for local-seg-id must be identical to the ring number of the TrCRF. The set vlan command assumes that any ring number you enter is in hexadecimal. The name elan-name local-seg-id segment-number command assumes that any value you enter for the local-seg-id is in decimal unless you enter it explicitly in hexadecimal. | ||
| ATM(lane-config-database)# | Assigns a segment number to the second emulated Token Ring LAN in the configuration database. The segment number you specify for local-seg-id must be identical to the ring number of the TrCRF. The set vlan command assumes that any ring number you enter is in hexadecimal. The name elan-name local-seg-id segment-number command assumes that any value you enter for the local-seg-id is in decimal unless you enter it explicitly in hexadecimal. Repeat this step, providing a different ELAN name and segment number for each additional source-route bridged ELAN in this switch cloud. | ||
| ATM(lane-config-database)# | Adds a database entry associating a specific client's ATM address with a specific restricted-membership ELAN. Repeat this step for each of the clients of each of the restricted-membership ELANs on the switch cloud, in each case specifying that client's ATM address and the name of the ELAN with which it is linked. | ||
| ATM(lane-config-database)# | Exits from database configuration mode and returns to global configuration mode. |
Once you have created the database entries as appropriate to the type and the membership conditions of the ELANs, you can enable the LECS on the selected ATM interface and switch by completing the following tasks, beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#interface atm number | If you are not currently configuring the interface, specifies the major ATM interface where the LECS is located and enters interface configuration mode. | ||
| ATM(config-if)#lane config auto-config-atm-address | Specifies that the LECS's ATM address will be computed by the automatic method. | ||
| ATM(config-if)#lane config database database-name | Binds the LECS's database name to the specified major interface, and enables the LECS. | ||
| ATM(config-if)#exit | Exits interface configuration mode. | ||
| ATM#copy running-config startup-config | Saves the configuration. |
For each Catalyst 5000 series switch ATM module that will participate in LANE, set up the necessary servers and clients for each ELAN and then display and record the server and client ATM addresses. Be sure to keep track of the switch ATM interface where the LECS will eventually be located.
If you are going to have only one default ELAN, you only need to set up one server. If you are going to have multiple ELANs, you can set up the server for another ELAN on a different subinterface on the same interface of this switch, or you can place it on a different switch.
When you set up a server and BUS on a switch, you can combine them with a client on the same subinterface, a client on a different subinterface, or no client at all on the switch.
Depending on where your clients and servers are located, perform one of the following tasks for each LANE subinterface:
To set up the LES/BUS for an ELAN, perform the following tasks beginning in global configuration mode.
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)#interface atm number[.subinterface-number] | Specifies the subinterface for the first ELAN on this switch and enters interface configuration mode. | ||
| ATM(config-if)#lane server-bus tokenring elan-name1 | Enables a LES/BUS for the first ELAN on the subinterface (you cannot configure more than one LES/BUS per subinterface). | ||
| Repeat Steps 1 and 2 for all LES/BUSs you want to configure on the ATM module. |
| ||
| ATM(config-if)#exit | Exits interface configuration mode. | ||
| ATM#copy running-config startup-config | Saves the configuration. |
If the ELAN specified in Step 2 is intended to have restricted membership in the LECS database, carefully consider whether or not you want to specify its name here. You will specify the name in the LECS database when it is set up. However, if you link the client to an ELAN in this step, and through some mistake it does not match the database entry linking the client to an ELAN, this client will not be allowed to join this ELAN or any other.
If you do decide to include the name of the ELAN linked to the client in Step 2 and later want to associate that client with a different ELAN, make the change in the LECS's database before you make the change for the client on this subinterface.
This section describes the following tasks for setting up a LEC:
The Catalyst 5000 series Token Ring LANE requires the following software:
 | Caution While VTP version 2 must be enabled on a Catalyst 5000 for Token Ring to function, do not use VTP to distribute VLAN configuration information between the switches. Configure the switches to operate in VTP transparent mode and manually configure the VLANs on each switch. |
When you set up a LEC, follow these rules and recommendations:
| VLAN Number | VLAN Name |
|---|---|
1 | default |
2...1002 | VLAN0002 through VLAN1002 |
1003 | trcrf-default |
1004 | VLAN1004 |
1005 | trbrf-default |
If you currently have a different ELAN name for VLAN 1 or VLAN 1003, you must change the ELAN name to default (for VLAN 1) or trcrf-default (for VLAN 1003) in the LECS database. The following example shows an LECS database configuration that specifies marktng as the ELAN name for VLAN 1003:
lane database test name marktng server-atm-address 47.0091810000000061705B8301.00400B020011.01 ! interface ATM0 no ip address no ip route-cache atm pvc 1 0 5 qsaal atm pvc 2 0 16 ilmi lane config auto-config-atm-address lane config database test ! interface ATM0.1 multipoint no ip route-cache lane server-bus tokenring marktng lane client tokenring 1003 marktng
You must change the ELAN name for VLAN 1003 from marktng to trcrf-default in the second and last lines of the display, as follows:
lane database test name default server-atm-address 47.0091810000000061705B8301.00400B020011.01 ! interface ATM0 no ip address no ip route-cache atm pvc 1 0 5 qsaal atm pvc 2 0 16 ilmi lane config auto-config-atm-address lane config database test ! interface ATM0.1 multipoint no ip route-cache lane server-bus tokenring default lane client tokenring 1003 trcrf-default
With Token Ring, to successfully route packets between ELANs, you can only set up one LEC for each TrBRF on an ATM module. For multiple ELANs with the same TrBRF to route packets, they must be configured on either separate ATM modules or connected via an external device.
If the TrBRF and TrCRF for which you are creating a LEC do not already exist, create the Token Ring VLANs by performing the following tasks beginning in privileged mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Console> (enable)set vlan vlan_num [name name] type trbrf [state
{active | suspend}] [mtu mtu] bridge bridge_number [stp {ieee | ibm | auto}]
| From the supervisor module, defines the TrBRF that you will associate to TrCRF as a parent | ||
| Console> (enable)set vlan vlan_num [name name] type trcrf [state
{active | suspend}] [mtu mtu] ring ring_number parent vlan_num [mode {srt |
srb}] [backupcrf {off | on}] [aremaxhop hopcount] [stemaxhop hopcount]
| From the supervisor module, defines the TrCRF for which you are creating a LEC. |
To set up the LEC for the Token Ring VLAN and corresponding ELAN, perform the following tasks on the ATM module beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM(config)# | Specifies the subinterface for an ELAN on this switch and enters interface configuration mode. | ||
| ATM(config-if)# | Creates a LEC for the first ELAN and specifies the VLAN number and the ELAN name to which to bind the LEC. | ||
| ATM(config-if)# | Exits configuration mode. | ||
| ATM(config)# | Saves the configuration |
The LANE protocol does not specify where any of the ELAN server entities should be located, but for the purpose of reliability and performance, Cisco implements these server components on its routers and LAN switches.
With Phase I LANE, only one LECS, capable of serving multiple ELANs, and only one LES per ELAN could exist for an ATM cloud. The Phase I LANE protocol did not allow for multiple LESs within an ELAN. Therefore, these components represented both single points of failure and potential bottlenecks for LANE service.
LANE LES/BUS and LECS redundancy corrects these limitations by allowing you to configure redundant LES/BUSs so that the LECs in an ELAN can automatically switch to a backup LES if the primary LES fails. The priority of the LES/BUS pairs is established by the order in which they are entered in the LECS database. LANE LES/BUS and LECS redundancy is always enabled. You can use this redundancy feature by configuring multiple servers.
LES/BUS and LECS redundancy works only with Cisco LECS and LES combinations. Third party LANE server components continue to interoperate with the LECS and LES/BUS function of Cisco routers and switches, but cannot take advantage of the redundancy features.
The following servers are single points of failure in the ATM LANE system:
LES/BUS and LECS redundancy eliminates these single points of failure.
To enable redundant LECSs, enter the multiple LECS addresses to the end ATM switches, which are used as central locations for the list of LECS addresses. After entering the LECS addresses, LANE components connected to the switches can obtain the global list of LECS addresses.
To enable LES/BUS and LEC redundancy, complete the following tasks beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Switch(config)#atm lecs-address address | Allows you to enter the multiple LECS addresses on the ATM switch. | ||
| ATM(config)#name elan-name server-atm-address les-address [indexn] | Specifies redundant LES/BUSs on the ATM module. Enter the command for each LES address on the ELAN. The index determines the priority; 0 is the highest priority. |
If enabled, ILMI sends keepalive messages on an ongoing basis on the active physical (PHY) to the switch, and the switch responds. If the response is not obtained for the last four polls, the ILMI timer times out and the Dual PHY changes from active PHY to backup PHY. This feature is useful only if the two PHYs are connected to two different switches.
By default, this feature is disabled. To enable it, start a session to the ATM module (using the session command), and then enter the following commands:
ATM> enable ATM# configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)# interface atm0 ATM(config-if)# atm ilmi-keepalive 4 ATM(config-if)# end ATM#
These commands enable the transmission of ILMI keepalive messages and set the time between ILMI keepalive messages to 4 seconds.
The ATM LANE Dual PHY module supports backward compatibility with ATM switches for UNI version 3.1. On startup, ILMI negotiates between UNI versions 3.0 and 3.1, which requires no configuration. If the ILMI link autodetermination is successfully enabled on the interface, the router or switch accepts the UNI version returned by ILMI. If the ILMI link autodetermination is unsuccessful or if ILMI is disabled, the UNI version defaults to 3.0. You can override the version number by entering the atm uni-version command. If ILMI is enabled when you enter the no version of the command, the UNI version is set to the version returned by ILMI and the link autodetermination is successful. Otherwise, the version reverts to 3.0. Enter the no atm uni-version command to override the UNI version.
With Fast Simple Server Redundancy Protocol (FSSRP), you can configure redundant LES/BUS pairs for each ELAN. With FSSRP, which differs from the previously implemented Simple Server Redundancy Protocol (SSRP), all configured LESs of an ELAN are active which means FSSRP-aware redundant LES/BUS pairs can accept join requests from any FSSRP-aware client.
LECs that are FSSRP aware have virtual circuits established to every single LES/BUS in the ELAN. Because virtual circuit connections already exist between all LECs and LES/BUS pairs in the ELAN, the LECs can switch over to another LES/BUS pair without any noticeable delay should a failure occur.
When you configure more than one LES/BUS pair for an ELAN, one LES/BUS takes precedence over others based on the order in which they are entered into the LECS database.
Configuring redundant LES/BUS pairs for an ELAN is a two-part process:
To configure the LES/BUS pairs, perform the following tasks beginning in privileged EXEC configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ATM#configure terminal | Enters global configuration mode. | ||
| | Specifies the major interface and enters subinterface configuration mode. | ||
| | Enables FSSRP on the major interface | ||
| | Specifies the subinterface for the first ELAN. | ||
| | Enables the LES/BUS for an ELAN on the subinterface (you cannot configure more than one LES/BUS per subinterface). | ||
| Repeat Steps 2 and 3 for all LES/BUSs you want to configure on this ATM module. |
| ||
| | Exits subinterface configuration mode. | ||
| | Verifies the LES/BUS configuration. |
This example shows how to specify the LES/BUS for an ELAN and verify the configuration:
ATM#configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)#interface atm0.1 ATM(config-subif)#lane server-bus tokenring default ATM(config-subif)#interface atm0.2 ATM(config-subif)#lane server-bus tokenring Eng_ELAN ATM(config-subif)#^Z ATM#show lane server LE Server ATM0.1 ELAN name: default Admin: up State: operational type: tokenring Max Frame Size: 4472 ATM address: 47.00918100000000E04FACB401.00100DAACC41.01 LECS used: 47.007900000000000000000000.00A03E000001.00 NOT yet connected LE Server ATM0.2 ELAN name: Eng_ELAN Admin: up State: operational type: tokenring Max Frame Size: 4472 ATM address: 47.00918100000000E04FACB401.00100DAACC41.02 LECS used: 47.007900000000000000000000.00A03E000001.00 NOT yet connected ATM#
To add the redundant LES/BUS pairs to the LECS, perform the following tasks beginning in privileged EXEC configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| | Displays the ATM address of the LES/BUS for the ELAN. | ||
| | Enters global configuration mode. | ||
| | Enters database configuration mode, specifying a LANE database name. | ||
| | Binds the name of the ELAN to the ATM addresses of the LES/BUS pairs in the order you want the services to fail over. | ||
| | In the configuration database, provides a default name of the ELAN. | ||
| | Exits from database configuration mode. | ||
| | Displays the LECS database configuration so that you can verify your changes. |
This example shows how to display the ATM address of the LES/BUS of the default ELAN, how to configure the LECS database for the default ELAN, and how to verify the configuration:
ATM#show lane server LE Server ATM0.1 ELAN name: default Admin: up State: operational type: ethernet Max Frame Size: 1516 ATM address: 47.00918100000000E04FACB401.00100DAACC41.01 LECS used: 47.007900000000000000000000.00A03E000001.00 NOT yet connected ATM#configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)#lane database LANE_Backbone ATM(lane-config-database)#name default server-atm-address 47.00918100000000E04FACB401.00100DAACC41.01 ATM(lane-config-database)#default-name default ATM(lane-config-database)#^Z ATM#show lane database LANE Config Server database table 'LANE_Backbone' default elan: default elan 'default': un-restricted server 47.00918100000000E04FACB401.00100DAACC41.01 (prio 0)
Once you have set up the LECs on the subinterfaces of an ATM module, you can display their ATM addresses by completing the following task in privileged EXEC mode:
| Command | Purpose |
|---|---|
Router#show lane | Displays the LES, BUS, and LEC ATM addresses. |
The command output shows all the subinterfaces configured for LANE. For each subinterface, the command displays and labels the ATM addresses that belong to the LES, BUS, and the LEC.
When you look at each ATM address, check the following items:
Enter the show lane command on each Catalyst 5000 series switch to verify the LANE setup before you set up the LECs on the next Catalyst 5000 series switch. Print the display or make a note of these ATM addresses so that you can use it when you set up the LECS database. At this point in the configuration process, the LECs are not normally operational.
After configuring LANE components on an interface or any of its subinterfaces, you can display their status on a specified subinterface or on an ELAN. To show LANE information, issue the following commands in privileged EXEC mode:
| Command | Purpose |
|---|---|
Router#show lane [interface atm 0 [subinterface-number | name elan-name]] [brief] | Displays the global and per-VCC LANE information for all the LANE components and ELANs configured on an interface or any of its subinterfaces. |
Router#show lane bus [interface atm 0 [subinterface-number] | name elan-name] [brief] | Displays the global and per-VCC LANE information for the BUS configured on any subinterface or ELAN. |
Router#show lane client [interface atm 0 [subinterface-number] | name elan-name] [brief] | Displays the global and per-VCC LANE information for all LECs configured on any subinterface or ELAN. |
Router#show lane config [interface atm 0] | Displays the global and per-VCC LANE information for the LECS configured on any interface. |
Router#show lane database [database-name] | Displays the LECS database. |
Router#show lane le-arp [interface atm 0 [subinterface-number] | name elan-name] | Displays the LANE Address Resolution Protocol (ARP) table of the LECs configured on the specified subinterface or ELAN. |
Router#show lane server [interface atm 0 [subinterface-number] | name elan-name] [brief] | Displays the global and per-VCC LANE information for the LES configured on a specified subinterface or ELAN. |
This section provides a configuration example composed of two Catalyst 5000 series switches and a LightStream 1010 ATM switch as illustrated in Figure 1.
For the example in Figure 1 the following assumptions apply:
To define the TrCRF, complete the following tasks:
Step 1 At the enable prompt, enter:
Console> (enable) set vlan 112 name crf112 type trcrf ring 112 parent 400 modesrb
Step 2 To verify the configuration of the new VLAN, enter the show vlan command.
The output indicates that crf112 has been added and that brf400 is its parent.
Console> (enable) show vlan 112 VLAN Name Status Mod/Ports, Vlans ---- -------------------------------- --------- ---------------------------- 112 crf112 active VLAN Type SAID MTU Parent RingNo BrdgNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ ------ ---- -------- ------ ------ 112 trcrf 100112 4472 400 0x112 - - srb 0 0 VLAN AREHops STEHops Backup CRF ---- ------- ------- ---------- 112 7 7 off Console> (enable)
To configure the LES/BUS and LEC, complete the following tasks:
Step 1 Set up the prefix of the ATM NSAP address for the switch.
Step 2 Start a session to the ATM module by entering the session 4 command. You see the following display:
Console> session 4 Trying ATM-4... Connected to ATM-4. Escape character is '^]'. ATM>
Step 3 Obtain the addresses of the LES and LES/BUS for later use by entering the enable command (to enable configuration mode) and the show lane default-atm-addresses command at the ATM prompt. You see the following display:
ATM> enable ATM# ATM# show lane default-atm-addresses interface atm0 interface ATM0: LANE Client: 47.0091810000000061705b7701.00400BFF0010.** LANE Server: 47.0091810000000061705b7701.00400BFF0011.** LANE Bus: 47.0091810000000061705b7701.00400BFF0012.** LANE Config Server: 47.0091810000000061705b7701.00400BFF0013.00 ATM#
Step 4 Using the LECS address obtained in Step 3, set the address of the default LECS in the LightStream 1010 switch by entering the configure terminal and atm lecs-address-default commands on the console of the LightStream 1010 switch. You see the following display:
Switch> enable Switch# Switch# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Switch(config)# atm lecs-address-default 47.0091810000000061705b7701.00400BFF0013.00 1 Switch(config)# end Switch#
The commands shown in this step configure the address of the LECS in the switch. The LECS ATM NSAP address is 47.0091810000000061705b7701.00400BFF0013.00. The sequence number of this LECS address, which is 1, means it is the first LECS in this switch.
Step 5 Save the configuration to NVRAM by entering the write memory command, as follows:
ATM# write memory
Step 6 Start a LES/BUS pair on Catalyst 5000 series switch 1 by entering the interface atm0 and the lane server-bus tokenring commands in global configuration mode. On the console of Catalyst 5000 series switch 1, enter the following commands:
ATM# configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)# interface atm0 ATM(config-subif)# lane server-bus tokenring crf112 ATM(config-subif)# end ATM#
The commands shown in this step start a LES/BUS pair and assign the ATM 0 interface to crf112. The ELAN name is crf112, and the interface on which this LES/BUS pair is configured is atm0. The ELAN name must be the same as the VLAN name assigned to the TrCRF.
Step 7 Save the configuration in NVRAM entering the write memory command, as follows:
ATM# write memory
Step 8 Set up the LECS database on the Catalyst 5000 series switch 1.
Enter the LES address obtained in Step 3 and replace the ** with the subinterface number of the interface on which the LES/BUS is to be configured. In this example, that number is 00. Enter the lane database database_name, the name elan_name server-atm-address atm_address command, the name elan_name local-seg-id segment_number, and the default-name elan_name commands at the ATM prompt. You see the following display:
ATM# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# lane database test
ATM(lane-config-database)# name trcf-default server-atm-address
47.0091810000000061705b7701.00400BFF0011.00
ATM (lane-config-database) name crf112 local-seg-id 0x112
ATM(lane-config-database)# default-name crf112
ATM(lane-config-database)# exit
ATM#
The commands shown in this step create the LECS database. The database name is test. The ELAN name is crf112. The ELAN segment number is 112. The LES ATM NSAP address is 47.0091810000000061705b7701.00400BFF0011.00.
Step 9 Save the configuration in NVRAM by entering the write memory command, as follows:
ATM# write memory
Step 10 Start and bind the LECS on the Catalyst 5000 series switch 1 by entering the interface atm0, the lane config database database_name, and the lane config auto-config-atm-address commands at the ATM prompt. You see the following display:
ATM# configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)# interface atm0 ATM(config-if)# lane config database test ATM(config-if)# lane config auto-config-atm-address ATM(config-if)# end ATM#
The commands shown in this step start the LECS. The database to use is test. The interface on which the LECS is configured is atm0.
Step 11 Save the configuration in NVRAM by entering the write memory command, as follows:
ATM# write memory
Step 12 Start the LEC on the Catalyst 5000 series switches 1 and 2 by entering the interface atm0.1 command and the lane client tokenring 112 crf112 command in configuration mode on the consoles of switches 1 and 2. The interface on which the LEC is configured is atm0.1. The ELAN name is default, and it is configured to emulate Token Ring. You see the following display:
ATM# configure terminal Enter configuration commands, one per line. End with CNTL/Z. ATM(config)# interface atm0.1 ATM(config-subif)# lane client tokenring 112 crf112 ATM(config-subif)# end ATM#
Step 13 Save the configuration in NVRAM by entering the write memory command, as follows:
ATM# write memory
There are no new or modified commands for the Token Ring LANE on the Catalyst 5000 ATM module feature. All commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.
There are no new or modified debug commands associated with the Token Ring LANE on the Catalyst 5000 ATM module feature. All commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.
BRF---Bridge relay function. As defined by the IEEE, an internal bridge function on a Token Ring switch that is responsible for forwarding frames between port groupings with the same logical ring number (CRFs). Within a BRF, source-route bridging or source-route transparent bridging can be used to forward frames. See also CRF.
BUS---broadcast and unknown server. Multicast server used in ELANs that is used to flood traffic addressed to an unknown destination and to forward multicast and broadcast traffic to the appropriate clients. See also ELAN.
CRF---Concentrator relay function. As defined by the IEEE, a logical grouping of ports on a Token Ring switch with the same ring number. Within a CRF, source-route switching is used to forward frames within a port group. Multiple CRFs may exist within a switch. The BRF forwards frames between CRFs. See also BRF.
ELAN---emulated LAN. ATM network in which an Ethernet or Token Ring LAN is emulated using a client-server model. ELANs are composed of an LEC, an LES, a BUS, and an LECS. Multiple ELANs can exist simultaneously on a single ATM network. ELANs are defined by the LANE specification. See also BUS, LANE, LEC, LECS, and LES.
ILMI---Interim Local Management Interface. Specification developed by the ATM Forum for incorporating network-management capabilities into the ATM UNI.
Interim Local Management Interface---See ILMIInterim Local Management Interface. Specification developed by the ATM Forum for incorporating network-management capabilities into the ATM UNI..
---LAN emulation. Technology that allows an ATM network to function as a LAN backbone. The ATM network must provide multicast and broadcast support, address mapping (MAC-to-ATM), SVC management, and a usable packet format. LANE also defines Ethernet and Token Ring ELANs. See also ELAN.
LEC---LAN emulation client. Entity in an end system that performs data forwarding, address resolution, and other control functions for a single ES within a single ELAN. An LEC also provides a standard LAN service interface to any higher-layer entity that interfaces to the LEC. Each LEC is identified by a unique ATM address, and is associated with one or more MAC addresses reachable through that ATM address. See also ELAN and LES.
LECS---LAN emulation configuration server. Entity that assigns individual LANE clients to particular ELANs by directing them to the LES that corresponds to the ELAN. There is logically one LECS per administrative domain, and this serves all ELANs within that domain. See also ELAN.
LES---LAN emulation server. Entity that implements the control function for a particular ELAN. There is only one logical LES per ELAN, and it is identified by a unique ATM address. See also ELAN.
TrBRF---See BRF.
TrCRF---See CRF.
UNI---User-Network Interface. ATM Forum specification that defines an interoperability standard for the interface between ATM-based products (a router or an ATM switch) located in a private network and the ATM switches located within the public carrier networks. Also used to describe similar connections in Frame Relay networks.
Posted: Fri Dec 10 19:05:20 PST 1999
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