Configuring ATM Modules

This chapter describes how to configure the ATM module, which provides connectivity to the ATM backbone. It also describes the configuration of the LAN Emulation (LANE) client and servers.

LANE permits an ATM network to be used as a LAN backbone for hubs, bridges, and Ethernet switches such as the Catalyst 5000 series switches. LANE also allows end stations to communicate through a LAN-to-ATM switch with an ATM-attached device, such as a file server, without requiring the traffic to pass through a more complex device such as a router. LANE requires a switch that supports User-Network Interface (UNI) 3.0 or 3.1 and point-to-multipoint signaling--for example, the Cisco LightStream family of switches.

Accessing the ATM LAN Emulation Module

You can open a session with the ATM module in the Catalyst 5000 series switch by entering the session mod_num command from the supervisor Console> prompt. 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.

The ATM module uses a subset of the Cisco IOS software. Generally, the Cisco IOS software works the same on the ATM module as it does on routers. Refer to "Command-Line Interfaces," for more information.

Default Configuration

The ATM LANE module has the following default configuration:

• The ILMI and signaling PVCs are set up.

• No LANE is configured.

• NVRAM contains no configuration information.

Customizing the Configuration

To configure the ATM module, you must use configuration mode. To enter configuration mode, enter the EXEC command configure 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]?

Terminal configuration means changing the run-time configuration. You can save the run-time configuration into the NVRAM. When you configure from memory, the run-time configuration is updated from the NVRAM. When you configure from the 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 the 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.

Configuring from the Terminal

To configure the ATM module from the terminal, complete these steps:

ATM# configure terminal
ATM (config)# interface atm 0
ATM (config)# lane client ethernet 1 man
ATM (config)# Ctrl-Z
ATM# write memory

Configuring from Nonvolatile Memory

You can configure the ATM module from NVRAM by reexecuting the configuration commands stored in NVRAM. To do so, enter this command in EXEC mode:

Implementing LANE

This section describes LANE components, prerequisite information, the procedures necessary to implement LANE, and other information about monitoring and maintaining LANE components.

Understanding LANE Components

You can set up an unlimited number of ELANs in an ATM cloud. A Catalyst 5000 series switch ATM module can participate in multiple ELANs.

• LANE Client (LEC)

A LEC emulates a LAN interface to higher-layer protocols and applications. It forwards data to other LANE components and performs LANE address-resolution functions.

Each LEC is a member of only one ELAN. However, a router or a Catalyst 5000 series switch ATM module can include LECs for multiple ELANs--one LEC for each member of ELAN.

If a router has LECs for multiple ELANs, the router can route traffic between the ELANs.

• LANE Server (LES)

• LANE broadcast-and-unknown server (BUS)

• LANE Configuration Server (LECS)

The LECS contains the database that determines the ELAN to which a device belongs. Each configuration LES can have a differently named database. Each LEC consults the LECS just once--when it first joins an ELAN--to determine which ELAN it should join. The LECS returns the ATM address of the LES for that ELAN.

At least one LECS is required per ATM LANE switch cloud.

The LECS database can have the following four types of entries:

• ELAN_name, ATM_address_of_LES pairs

• LEC_MAC_address, ELAN_name pairs

• LEC_ATM_template, ELAN_name pairs

• Default ELAN name

ELAN names must be unique on an interface. If two interfaces participate in LANE, the second interface might be in a different switch cloud.

Following LANE Guidelines

Before you implement LANE, be aware of the following:

• All ATM switches have identical lists of the global LECS addresses with the identical priorities.

• The operating LECSs must use exactly the same configuration database. Load the configuration table data by entering the config net command. This method minimizes errors and enables the database to be maintained centrally.

• In an underlying ATM network failure, there can be multiple master LECs and multiple active LESs for the same ELAN, yielding a partitioned network. Clients continue to operate normally, but transmission between different partitions of the network is not possible. The system recovers when the network break is repaired.

• The LANE subsystem can handle up to 16 LECS addresses.

• The number of LESs that can be defined per ELAN is unlimited.

• When a LECS switchover occurs, no previously joined clients are affected.

• In a LES/BUS switchover, there is a momentary loss of clients until all clients are transferred to the new LES/BUS.

• LECSs automatically come up as masters until a higher level LECS tells them otherwise.

• When a higher priority LES comes online, it bumps the current LES off the same ELAN. For a short time after a power on, some clients might change from one LES to another, depending upon the order of the LESs coming up.

• If no specified LES is up or connected to the master LECS, and more than one LES is defined for an ELAN, the LECS rejects any configuration request for that specific ELAN.

• Changes made to the list of LECS addresses on ATM switches can take up to one minute to propagate through the network. Changes made to the configuration database regarding LES addresses take effect almost immediately.

• If no designated LECS is operational or reachable, the ATM Forum-defined "well-known" LECS address is used.

• The LECS can be overridden on any subinterface by entering these commands:

  -- lane auto-config-atm-address

  
  

  -- lane fixed-config-atm-address

  
  

  -- lane config-atm-address atm-address-template

  
  

To avoid affecting the LES/BUS/LEC redundancy, do not override any LECS, LES, or BUS addresses.

Setting Up a LANE Plan

Before implementing LANE, perform these tasks:

LANE Configuration Procedures

Configuring LANE involves the following tasks:

• Displaying ATM Addresses

• Connecting Dual PHYs to the Same Switch

• Connecting Dual PHYs to Different Switches

• Configuring the LECS ATM Address on a LightStream 1010 ATM Switch

• Setting Up the LES/BUS

• Setting Up the LECS Database

  • Setting Up the LECS Database for the Default ELAN

  • Setting Up the LECS Database for Unrestricted-Membership ELANs

  • Setting Up the LECS Database for Restricted-Membership ELANs

• Starting and Binding the LECS

• Setting up the LECs

• Verifying the Setup

• Monitoring and Maintaining LANE Components

Displaying ATM Addresses

You can display the default ATM addresses for the LECS, LES, BUS, and LEC. Use this information to configure LECS addresses in the ATM switch and to configure the LECS database.

Connecting Dual PHYs to the Same Switch

To display default ATM addresses, enter this command:

After you enter the show lane default-atm-addresses command, you see this display:

ATM# show lane default-atm-addresses 
interface ATM0:
LANE Client:        47.00918100000000613E5D1101.00400BF00440.**
LANE Server:        47.00918100000000613E5D1101.00400BF00441.**
LANE Bus:           47.00918100000000613E5D1101.00400BF00442.**
LANE Config Server: 47.00918100000000613E5D1101.00400BF00443.00

In this display, ** is the subinterface number byte in hexadecimal. Record the addresses for later use.

Connecting Dual PHYs to Different Switches

If the two PHYs on the ATM Dual PHY module connect to different switches, you must determine the addresses to use if the first PHY goes down. Complete these steps:

Ensure that the ATM dual PHY module connects to the switch, that the interface is up, and that ILMI PVC is enabled.

This display indicates that the module could not get the ATM prefix through ILMI from the switch:

ATM# show lane default-atm-addresses 
interface ATM0:
LANE Client:        ...00400BF00440.**
LANE Server:        ...00400BF00441.**
LANE Bus:           ...00400BF00442.**
LANE Config Server: ...00400BF00443.00

In this display, ** is the subinterface number byte in hexadecimal.

Displaying the ATM addresses of LESs and LECs as you configure them can save you the time and effort of computing the addresses. These savings can be considerable when you set up the LECS database--especially for ELANs with restricted membership. Note the LECS ATM address so you can configure it on each ATM subinterface where a LES and BUS are configured.

Configuring the LECS ATM Address on a LightStream 1010 ATM Switch

You must program all LECS addresses into each ATM switch, such as a LightStream 1010 switch, that is connected to a participant in your LANE network. Programming the addresses allows the LESs and LECs to determine the LECs addresses dynamically through ILMI.

To configure a server ATM address on a LightStream 1010 ATM switch, complete these steps for each connected LightStream 1010 ATM switch:

Setting Up the LES/BUS

To set up the LES/BUS for an ELAN, complete these steps:

Setting Up the LECS Database

Complete the steps in this section to set up the LECS database. If you have more than one LECS, make sure that all databases are identical. If you have more than one server in an ELAN, servers take precedence over other servers based on when they are entered into the LECS database. Note that if a dual PHY module acts as a server, you must enter the predetermined address of each PHY.

Setting Up the LECS Database for the Default ELAN

When you configure a Catalyst 5000 series switch as the LECS for one default ELAN, you provide a name for the database, the ATM address of the LES for the ELAN, and a default name for the ELAN. In addition, you indicate that the LECS ATM address is to be computed automatically.

When you set up a database of only a default, unrestricted ELAN, you do not need to specify where the LANE LECs are located. That is, when you set up the LECS database for a single default ELAN, you do not have to provide any database entries that link the ATM addresses of any LECs with the ELAN name.

To set up the LECS for the default ELAN, complete these steps:

If you set up only a default ELAN, the elan-name value in Step 2 is the same as the default ELAN name you provided in Step 3. If you use both PHYs on the ATM LANE dual PHY module, you must use LES/BUS/LECS redundancy.

Setting Up the LECS Database for Unrestricted-Membership ELANs

When you set up a database for unrestricted-membership ELANs, you create database entries that link the name of each ELAN to the ATM address of its LES.

However, you might choose not to specify where the LECs are located. That is, when you set up the LECS database, you do not have to provide any database entries that link the ATM addresses or MAC addresses of any LECs with the ELAN name.

To configure a router as the LECS for multiple ELANs with unrestricted membership, complete these steps in global configuration mode:

Setting Up the LECS Database for Restricted-Membership ELANs

When you set up the database for restricted-membership ELANs, you create database entries that link the name of each ELAN to the ATM address of its LES.

However, you also must 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 LEC of that ELAN with the name of that ELAN.

Those LEC database entries specify the LECs that are allowed to join the ELAN. When a LEC requests that the LECS indicate which ELAN it is to join, the LECS consults its database and then responds as configured.

When LECs for the same restricted-membership ELAN are located in multiple Catalyst 5000 series ATM modules, you must link each LEC ATM address or MAC address explicitly with the name of the ELAN. As a result, you must configure as many LEC entries (Step 5 in the following procedure) as you have LECs for ELANs in all the ATM modules of Catalyst 5000 series switches. Each LEC will have a different ATM address in the database entries.

To set up the LECS for ELANs with restricted membership, complete these steps in global configuration mode:

Starting and Binding the LECS

To start and bind the LECS, complete these steps:

Setting up the LECs

On any Catalyst 5000 series switch, you can set up one LEC for one ELAN or multiple LECs for multiple ELANs. You can set up a LEC for a given ELAN on any Catalyst 5000 series switch you choose to participate in that ELAN. After you set up the interface for the VLAN, you must link the VLAN number with the ELAN name.

Verifying the Setup

Once you set up the LECs on the subinterfaces of an ATM module, you can display their ATM addresses by entering this command in EXEC mode:

This command output shows all subinterfaces configured for LANE. For each subinterface, the command displays and labels the ATM addresses that belong to the LES, BUS, and LEC.

When you look at each ATM address, note the following:

• The prefix is the one you set up on the switch.

• The end-system identifier (ESI) field reflects the base address of the pool of MAC addresses assigned to the ATM interface plus a value that represents the specific LANE component.

• The selector byte is the same number as the subinterface (converted to hexadecimal).

Repeat the above task on each Catalyst 5000 series switch before you set up the LECs on the next Catalyst 5000 series switch. Print the display or note these ATM addresses so that you can use it when you set up the LECS database.

Monitoring and Maintaining LANE Components

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, complete these steps in EXEC mode:

Configuring Specialized LANE Features

To configure specialized LANE features, perform the appropriate tasks in this section.

Configuring LES/BUS/LECS Redundancy

LES/BUS/LECS redundancy allows you to configure redundant LESs and BUSs so that the LECs in an ELAN can switch automatically to a backup LES if the primary LES fails. The priority of the LES/BUS pairs is established by the order they are entered in the LECS database.

LANE Protocol

The LANE protocol does not specify where any of the ELAN server entities should be located, but for reliability and performance, we recommend implementing these server components on your 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.

LES/BUS/LECS redundancy corrects these limitations by allowing backup LECS and LES servers for an ELAN. LES/BUS/LECS redundancy is always enabled. You can use this redundancy feature by configuring multiple servers.

LES/BUS/LECS redundancy works only with Cisco LECS and LES combinations. Third party LANE components continue to interoperate with the LECS and LES function of Cisco routers but cannot take advantage of the redundancy features.

The following three servers are single points of failure in the ATM LANE system:

• LECS

• LES

• BUS

LES/BUS/LEC redundancy eliminates these single points of failure. To configure LES/BUS/LECS redundancy, use the procedure in the following section.

Procedure

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/LECS redundancy, complete these steps:

The index determines the priority; 0 is the highest priority.

Configuring VTP

When you add VLANs to a Catalyst 5000 series switch in a management domain, VTP distributes information automatically to other trunks of all of the devices in the domain. The VTP is transmitted on all trunk connections, including Inter-Switch Link (ISL), IEEE 802.10, and LANE. By default, VTP is disabled on the Catalyst 5000 series switch ATM module; you must explicitly enable it. VTP works only with Catalyst 5000 series software release 2.1 or later and ATM software release 3.1 or later.

Setting Up a LEC Using VTP

VTP allows you to set up VLAN-to-LEC/ELAN mapping and establish LECs on the ATM module.

The name default in the set vlan command is the ELAN name for VLAN 1. The value vlan_num represents the VLAN number to configure, and elan_name is the name of the ELAN.

You can use VTP to set up a LEC in either transparent or nontransparent mode. When you enable VTP and your switch is in transparent mode, entering the set vlan vlan_num [name elan_name] command creates LECs on all ATM modules of only the switch on which you entered the command.

In nontransparent mode, entering the set vlan vlan_num [name elan_name] command from the supervisor module of any Catalyst 5000 series switch automatically creates a LEC for that VLAN/ELAN-name pair on all ATM modules on Catalyst 5000 series switches in that VTP domain.

To find your current mode and domain, enter the show vtp domain command.

Setting Up VTP

When you set up a LEC using VTP, these prerequisites apply:

When you enter the set vlan vlan_num [name elan_name] command in transparent mode and do not specify the optional name elan_name, the software uses the names listed in Table 5-1 by default:

• For VTP to successfully set up LECs on ATM edge devices in an ATM cloud, the default ELAN must be operational on the ATM edge devices and must be named default.

• If you currently have a different ELAN name for VLAN 1, you must change the ELAN name to default in the LECS database.This example shows a LECS database configuration that specifies marktng as the ELAN name for VLAN 1:

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 ethernet marktng
lane client ethernet 1 marktng
You must change the ELAN name for VLAN 1 from marktng to 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 ethernet default
lane client ethernet 1 default

The last line of the above display appears automatically after VTP is enabled.

To enable VTP for VLAN 1, complete these steps:

Enter the no VTP enable command to disable VTP.

Configuring Output Throttling

You can configure output throttling on the Catalyst 5000 series switch ATM module. Output throttling applies to both LANE and PVCs. Per-VC pacing is not supported.

To set the output rate to the default of 155 Mbps, complete these steps:

Enabling ILMI Keepalive Timeout

If enabled, ILMI sends keepalive messages on an ongoing basis on the active 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 switches from active PHY to backup PHY. This feature is useful only if the two PHYs are connected to two different switches.

ATM> enable
ATM# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
ATM(config)# int atm0
ATM(config-if)# atm ilmi-keepalive 4
ATM(config-if)# end
ATM#

Using UNI 3.1 Signaling Support

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, requiring no configuration. If the ILMI link autodetermination is successfully enabled on the interface, the router 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 value 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 {3.0 | 3.1} command to override the UNI version.

Setting Up ATM LANE Configuration Examples

The examples in this section show how to set up an ATM LANE configuration in a Catalyst 5000 series switch ATM module.

Example Configuration 1

Figure 5-1 shows a configuration of two Catalyst 5000 series switches (Catalyst 5000 series Switch 1 and Catalyst 5000 series Switch 2) and a LightStream 1010 ATM switch.

Example Configuration 1 Assumptions

In example configuration 1, these assumptions apply:

• The LightStream 1010 ATM switch is used.

• Catalyst 5000 series switches with the ATM modules installed are running ATM software release 3.1 or later.

• Catalyst 5000 series Switch 1 runs the LES/BUS and LECS on interface atm0 and the LEC on interface atm0.1.

• Catalyst 5000 series Switch 2 runs LEC on interface atm0.1.

• The ATM module is installed in slot 4 of both Catalyst 5000 series switches.

• You can change the ELAN name by entering the set vlan vlan_num [name elan_name] command.

• The ELAN names shown in Table 5-2 are used.

Example Configuration 1 Procedure

To set up LANE on the configuration in Figure 5-1, perform these steps:

Step 1 Set up the prefix of the ATM Network Service Access Point (NSAP) address for the switch.

The LightStream 1010 ATM switch provides a default prefix.

Step 2 Start a session to the ATM module by entering the session 4 command. You see this display:

Console> session 4
Trying ATM-4...
Connected to ATM-4.
Escape character is '^]'.
ATM>

Step 3 Obtain the LES and LES/BUS addresses for later use by entering the enable command (to enable configuration mode) and the show lane default command at the ATM prompt. You see this display:

ATM> enable
ATM#
ATM# show lane default
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#


---

Note The two asterisks (**) represent the subinterface number byte in hexadecimal.

---

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 atm_address commands on the console of the LightStream 1010 switch. You see this display:

Switch> enable
Switch#
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# atm lecs-address 47.0091810000000061705b7701.00400BFF0013.00 1
Switch(config)# end
Switch#

The commands shown in this step configure the LECS address 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 as follows:

ATM# write memory

Step 6 Start up a LES/BUS pair on Catalyst 5000 series Switch 1 by entering the interface atm0 and the lane server-bus ethernet default commands in configuration mode. On the console of Catalyst 5000 series Switch 1, enter these commands:

ATM# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-subif)# lane server-bus ethernet default
ATM(config-subif)# end
ATM#

The commands shown in this step start a LES/BUS pair. The ELAN name is default, and the interface on which this LES/BUS pair is configured is atm0.

Step 7 Save the configuration as follows:

ATM# write memory

Step 8 Set up the LECS database on the Catalyst 5000 series Switch 1.

Enter the LANE server address obtained in Step 3 and replace the ** with the subinterface number of the interface in which the LES/BUS is to be configured. In this example, that number is 00. Enter the lane database database_name command, the name elan_name server-atm-address atm_address command, and the default-name elan_name commands at the ATM prompt. You see this display:

ATM# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# lane database test
ATM(lane-config-database)# name default server-atm-address
47.0091810000000061705b7701.00400BFF0011.00
ATM(lane-config-database)# default-name default
ATM(lane-config-database)# end
ATM#

The commands shown in this step create the LECS database. The database name is test. The ELAN name is default. The LES ATM NSAP address is 47.0091810000000061705b7701.00400BFF0011.00.

Step 9 Save the configuration as follows:

ATM# write memory

Step 10 Start and bind the LECS on the Catalyst 5000 series Switch 1 by entering the interface atm0 command, the lane config database database_name command, and the lane config auto-config-atm-address command at the ATM prompt. You see this display:

ATM# config 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 name to use is test. The interface on which the LECS is configured is atm0.

Step 11 Save the configuration 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 ethernet 1 default 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 Ethernet. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.1
ATM(config-subif)# lane client ethernet 1 default
ATM(config-subif)# end
ATM#

Step 13 Save the configuration as follows:

ATM# write memory

Step 14 Create a LES/BUS pair on Catalyst 5000 series Switch 1 for VLAN 2 by entering the interface atm0.2 command and the lane server-bus ethernet VLAN0002 command in configuration mode. You see this display:

ATM# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config-subif)# interface atm0.2
ATM(config-subif)# lane server-bus ethernet VLAN0002
ATM(config-subif)# end
ATM#

Step 15 Save the configuration as follows:

ATM# write memory

Step 16 Configure the address of the new LES/BUS pair in the LECS database on Catalyst 5000 series Switch 1 by entering the lane database test command and the name VLAN0002 server-atm-address atm_address command in configuration mode. You see this display:

ATM# configure terminal
ATM(config)# lane database test
ATM(lane-config-database)# name VLAN0002 server-atm-address 47.0091810000000061705b7701.00400BFF0011.02
ATM(lane-config-database)# end
ATM#

Step 17 Save the configuration as follows:

ATM# write memory

Step 18 Start the new LEC on Catalyst 5000 series Switch 2 by entering the interface atm0.2 command and the lane client ethernet 2 VLAN0002 command in configuration mode. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.2
ATM(config-subif)# lane client ethernet 2 VLAN0002
ATM(config-subif)# end
ATM#

Step 19 Save the configuration as follows:

ATM# write memory

Example Configuration 2

Figure 5-2 shows three Catalyst 5000 series switches (Catalyst 5000 series Switch 1, Switch 2, and Switch 3) and a LightStream 1010 ATM switch. LES/BUS/LECS redundancy is configured. Switches 1 and 2 both have one LES/BUS/LECS for every ELAN. Switch 1 is the master server, and Switch 2 is the backup server. If Switch 1 fails, Switch 2 provides the LES/BUS/LECS components of the ELAN. Once Switch 1 recovers, it becomes the master server again.

Example Configuration 2 Assumptions

In Figure 5-2, these assumptions apply:

• The Catalyst 5000 series Switch 1 is the master. It runs the LES/BUS and LECS on interface atm0 and runs the LEC on interface atm0.1.

• The Catalyst 5000 series Switch 2 is the backup server. It runs LES/BUS and LECS on interface atm0 and runs the LEC on interface atm0.1.

• The Catalyst 5000 series Switch 3 runs the LEC on interface atm0.1.

• The ATM module is installed in slot 4 of each Catalyst 5000 series switch.

Example Configuration 2 Procedure

To set up the configuration in Figure 5-2, perform these steps:

Step 1 Set up the prefix of the ATM NSAP address for the switch.

The LightStream 1010 ATM switch provides a default prefix.

Step 2 Establish a connection with the ATM module from Switch 1 by entering the session command. You see this display:

Console> session 4
Trying ATM-4...
Connected to ATM-4.
Escape character is '^]'.

Step 3 Obtain the LES and LES/BUS addresses for later use by entering the show lane default command. You see this display:

ATM> show lane default
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>


---

Note The two asterisks (**) represent the subinterface number byte displayed in hexadecimal.

---

Step 4 Establish a connection to the ATM module from Switch 2 by entering the session command. You see this display:

Console> session 4
Trying ATM-4...
Connected to ATM-4.
Escape character is '^]'.

Step 5 Obtain the LES and LES/BUS addresses for later use by entering the show lane default command from privileged mode. You see this display:

ATM>
ATM> enable
ATM#
ATM# show lane default
interface ATM0:
LANE Client: 47.0091810000000061705b7701.00400B583040.**
LANE Server: 47.0091810000000061705b7701.00400B583041.**
LANE Bus: 47.0091810000000061705b7701.00400B583042.**
LANE Config Server: 47.0091810000000061705b7701.00400B583043.00
ATM#


---

Note The two asterisks (**) represent the subinterface number byte displayed in hexadecimal.

---

Step 6 Set up the LECS database on Switches 1 and 2. Enter the LES addresses obtained in Steps 3 and 5 and replace the two asterisks (**) with the subinterface numbers of the interfaces in which the LES/BUS is to be configured. In this example, that number is 00. Enter the lane database database-name command, the name elan_name server-atm-address atm_address command, and the default-name elan_name commands in configuration mode on both Switch 1 and Switch 2.

---

Note The order of the entries is critical and should be the same on both the primary and secondary Catalyst 5000 series switches for this configuration to work effectively.

---

After entering these commands, you see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# lane database test
ATM(lane-config-database)# name default server-atm-address
47.0091810000000061705b7701.00400BFF0011.00
ATM(lane-config-database)# name default server-atm-address
47.0091810000000061705b7701.00400B583041.00
ATM(lane-config-database)# default-name default
ATM(lane-config-database)# end
ATM#

In this example, the name of the database is test. The name of the ELAN is default. The first entry is the primary LES. The second entry is the backup LES. The primary LES ATM NSAP address is 47.0091810000000061705b7701.00400BFF0011.00. The backup LES ATM NSAP address is 47.0091810000000061705b7701.00400B583041.00.

Step 7 Save the configuration as follows:

ATM# write memory

Step 8 Start and bind the LECS on both the Catalyst 5000 series Switches 1 and 2 by entering the interface atm0 command, the lane config database database_name command, and the lane config auto-config-atm-address command in configuration mode on both Switch 1 and Switch 2. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-if)# lane config test
ATM(config-if)# lane config auto-config-atm-address
ATM(config-if)# end
ATM#

In this example, the database name is test and the interface on which the LECS is configured is atm0.

Step 9 Save the configuration as follows:

ATM# write memory

Step 10 Start up a LES/BUS pair on Switch 1 and Switch 2 by entering the interface atm0 command and the lane server-bus ethernet default command on the consoles of Switch 1 and Switch 2. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-subif)# lane server-bus ethernet default
ATM(config-subif)# end
ATM#

In this example, the ELAN name is default and the interface on which this LES/BUS pair is configured is atm0.

Step 11 Save the configuration as follows:

ATM# write memory

Step 12 Set the LECS addresses on Switches 1 and 2 in the ATM switch by entering the atm lecs-address atm_address command in configuration mode on the console of the LightStream 1010 switch for each Catalyst 5000 series switch. These commands configure the address of the primary and the backup LECSs in the ATM switch, in the order presented on the screen. Enter the LANE configuration server address obtained in Steps 3 and 5. You see this display:

ATM> enable
ATM# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# atm lecs-address 47.0091810000000061705b7701.00400BFF0013.00 1
ATM(config)# atm lecs-address 47.0091810000000061705b7701.00400B583043.00 2
ATM(config)# end
ATM#

Step 13 Save the configuration as follows:

ATM# write memory

Step 14 Start the LEC on Switches 1, 2, and 3 by entering the interface atm0.1 command and the lane client ethernet 1 default command in configuration mode on the consoles of Switches 1, 2, and 3. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.1
ATM(config-subif)# lane client ethernet 1 default
ATM(config-subif)# end
ATM#

The interface on which the LEC is configured is atm0.1. The ELAN name is default, and it is configured to emulate Ethernet.

Step 15 Save the configuration as follows:

ATM# write memory


---

Note To use VTP to create the LEC, see the section "Configuring VTP."

---

Step 16 Create a LES/BUS pair on Switches 1 and 2 for VLAN 2. Enter the interface atm0.2 command and the lane server-bus ethernet VLAN 0002 command in configuration mode on the consoles of Switches 1 and 2. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config-subif)# interface atm0.2
ATM(config-subif)# lane server-bus ethernet VLAN0002
ATM(config-subif)# end
ATM#

Step 17 Save the configuration as follows:

ATM# write memory

Step 18 Configure the address of the new LES/BUS pair in the LECS database on Switch 1. Enter the name elan_name server-atm-address atm_address commands at the ATM prompt:

ATM# configure terminal
ATM(config)# lane database test
ATM(lane-config-database)# name VLAN0002 server-atm-address
47.0091810000000061705b7701.00400BFF0011.02
ATM(lane-config-database)# name VLAN0002 server-atm-address
47.0091810000000061705b7701.00400B583041.02
ATM(lane-config-database)# end
ATM#

Step 19 Save the configuration as follows:

ATM# write memory

Step 20 Start the new LEC on Switch 3 by entering the interface atm0.2 command and the lane client ethernet 2 VLAN0002 command on the console of Switch 3.

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.2
ATM(config-subif)# lane client ethernet 2 VLAN0002
ATM(config-subif)# end
ATM#

Step 21 Save the configuration as follows:

ATM# write memory

Example Configuration 3

Figure 5-3 shows two ATM switches in an ATM cloud. ATM Switch 1 is connected to two Catalyst 5000 series switches (Catalyst 5000 series Switch 1 and Catalyst 5000 series Switch 2), which have ATM dual PHY modules. ATM Switch 2 is also connected to Catalyst 5000 series Switch 1 and Catalyst 5000 series Switch 2. If PHY A on Catalyst 5000 series Switch 1 is lost, data continues to flow to Catalyst 5000 series Switch 2 on PHY B, showing dual-PHY redundancy.

Example Configuration 3 Assumptions

In Figure 5-3, these assumptions apply:

• The LightStream 1010 switch is used.

• Catalyst 5000 series switches with the ATM modules installed are running ATM software release 3.1 or later.

• Catalyst 5000 series Switch 1 runs the LECS and LES/BUS on interface atm0 and the LEC on interface atm0.1.

• Catalyst 5000 series Switch 2 runs LEC on interface atm0.1.

• The ATM module is installed in slot 4 of the Catalyst 5000 series switches.

• You can change the ELAN name by entering the set vlan vlan_num [name] command.

Example Configuration 3 Procedure

To set up LANE on the configuration in Figure 5-3, perform these steps:

Step 1 Set up the prefix of the ATM NSAP address for the switch.

The LightStream 1010 ATM switch provides a default prefix.

Step 2 Establish a connection to the ATM module by entering the session command at the Catalyst 5000 series switch console prompt. You see this display:

Console> session 4
Trying ATM-4...
Connected to ATM-4.
Escape character is '^]'.

Step 3 Obtain the LECS and LES/BUS addresses for later use by entering the show lane default command in privileged mode at the ATM prompt. You see this display:

ATM> enable
ATM#
ATM# show lane default
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#


---

Note The two asterisks (**) represent the subinterface number byte displayed in hexadecimal.

---

Step 4 Access path B by entering the interface atm0 and the atm preferred phy B commands in configuration mode. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-subif)# atm preferred phy B
ATM(config-subif)# end
ATM#

Wait for approximately one minute while the PHY B comes up.

Step 5 Enter the show lane default command. The two asterisks (**) represent the subinterface number byte displayed in hexadecimal. You see this display:

ATM# show lane default
interface ATM0:
LANE Client: 47.0091810000000061705b8301.00400BFF0010.**
LANE Server: 47.0091810000000061705b8301.00400BFF0011.**
LANE Bus: 47.0091810000000061705b8301.00400BFF0012.**
LANE Config Server: 47.0091810000000061705b8301.00400BFF0013.00
ATM#

Step 6 Return to PHY A by entering the interface atm0 and the atm preferred phy A commands in configuration mode. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-subif)# atm preferred phy A
ATM(config-subif)# end
ATM#

Step 7 Set the address of the default LECS in the ATM switches by entering the addresses obtained in Steps 3 and 4. Enter the atm lecs-address atm_address command on the console of the LightStream 1010 Switch 1. These commands configure the address of the primary and the backup LECSs in the ATM switches in the specific order entered. Only one LECS runs on the Catalyst 5000 series Switch 1, but the address (the first 13 bytes) changes if PHY B is used instead of PHY A. After entering the commands, you see this display:

ATM> enable
ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# atm lecs-address 47.0091810000000061705b7701.00400BFF0013.00 1
ATM(config)# atm lecs-address 47.0091810000000061705b8301.00400BFF0013.00 2
ATM(config)# end
ATM#

Step 8 Save the configuration as follows:

ATM# write memory

Step 9 Enter the interface atm0 and lane server-bus ethernet default commands in configuration mode on the console of Catalyst 5000 series Switch 1. These commands start a LES/BUS pair. The ELAN name is default. The interface on which this LES/BUS pair is configured is atm0. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-subif)# lane server-bus ethernet default
ATM(config-subif)# end
ATM#

Step 10 Save the configuration as follows:

ATM# write memory

Step 11 Configure the LECS database of the Catalyst 5000 series Switch 1 by entering the lane database database_name command, the name elan_name server-atm-address atm address command, and the default-name elan_name command. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# lane database test
ATM(lane-config-database)# name default server-atm-address
47.0091810000000061705b7701.00400BFF0011.00
ATM(lane-config-database)#name default server-atm-address
47.0091810000000061705b8301.00400BFF0011.00
ATM(lane-config-database)# default-name default
ATM(lane-config-database)# end
ATM#

Enter the LANE server addresses obtained in Steps 3 and 4. Replace the two asterisks (**) with the subinterface number of the interface in which the LES/BUS is to be configured. In this example, the number is 00. These commands create the LECS database. The name of the database is test. The name of the ELAN is default.

The ATM NSAP address of the LES is 47.0091810000000061705b7701.00400BFF0011.00. The display in Step 3 shows this LANE BUS address.

The ATM NSAP address of the LES is 47.0091810000000061705b8301.00400BFF0011.00. The display in Step 4 shows this LANE BUS address.

Step 12 Save the configuration as follows:

ATM# write memory

Step 13 Start and bind the LECS on the Catalyst 5000 series Switch 1 by entering the interface atm0 command, the lane config database database_name command, and the lane config auto-config-atm-address command in configuration mode at the ATM prompt. The database name is test. The interface on which the LECS is configured is atm0. After entering these commands, you see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0
ATM(config-if)# lane config test
ATM(config-if)# lane config auto-config-atm-address
ATM(config-if)# end
ATM#

Step 14 Save the configuration as follows:

ATM# write memory

Step 15 Start a LEC on the Catalyst 5000 series Switches 1 and 2 by entering the interface atm0.1 and lane client ethernet 1 default commands in configuration mode on the consoles of each Catalyst 5000 series switch. The interface on which the LEC is configured is atm0.1. The ELAN name is default, and it is configured to emulate Ethernet. After entering the commands, you see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.1
ATM(config-subif)# lane client ethernet 1 default
ATM(config-subif)# end
ATM#

Step 16 Save the configuration as follows:

ATM# write memory

Step 17 Create a LES/BUS pair on the Catalyst series Switch 1 for VLAN 2 by entering the interface atm0.2 and lane server-bus ethernet VLAN0002 commands in configuration mode. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config-subif)# interface atm0.2
ATM(config-subif)# lane server-bus ethernet VLAN0002
ATM(config-subif)# end
ATM#

Step 18 Save the configuration as follows:

ATM# write memory

Step 19 Configure the address of the new LES/BUS pair in the LECS database on the Catalyst 5000 series Switch 1 by entering the lane database database_name and name elan_name server-atm-address atm_address commands in configuration mode. You see this display:

ATM# configure terminal
ATM(config)# lane database test
ATM(lane-config-database)# name VLAN0002 server-atm-address
47.0091810000000061705b7701.00400BFF0011.02
ATM(lane-config-database)# name VLAN0002 server-atm-address
47.0091810000000061705b8301.00400BFF0011.02
ATM(lane-config-database)# end
ATM#

Step 20 Save the configuration as follows:

ATM# write memory

Step 21 Start the new LEC on the Catalyst 5000 series Switch 2 by entering the interface atm0.2 and lane client ethernet 2 VLAN0002 commands in configuration mode on the console of Catalyst 5000 series Switch 2. You see this display:

ATM# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ATM(config)# interface atm0.2
ATM(config-subif)# lane client ethernet 2 VLAN0002
ATM(config-subif)# end
ATM#

Step 22 Save the configuration as follows:

ATM# write memory
ATM#

Understanding LANE

LANE provides the following:

• Connectivity between ATM-attached stations and LAN-attached stations

• Connectivity between LAN-attached stations across an ATM network

Because LANE connectivity is defined at the MAC layer, upper-protocol layer functions of LAN applications can continue unchanged when the devices join ELANs. This feature protects corporate investments in legacy LAN applications.

An ATM network can support multiple independent ELANs. End-system membership in any of the ELANs is independent of the physical location of the end system. This characteristic simplifies hardware moves and changes. In addition, the end systems can move easily from one ELAN to another, whether or not the hardware moves. Figure 5-4 shows an ATM LANE configuration.

Defining LANE Operation and Communication

Communication among LANE components is ordinarily handled by several types of switched virtual channel circuits (VCCs). Some VCCs are unidirectional; others are bidirectional. Some are point-to-point, and others are point-to-multipoint. Figure 5-5 illustrates the various types of VCCs.

Comparing VLANs and ELANs

The Catalyst 5000 series switch supports a port-centric VLAN configuration. All end stations connected to ports belong to the same VLAN and are assigned to the same VLAN number. The VLAN number is only significant to the Catalyst 5000 series switch.

On an ATM network, an emulated LAN is called an ELAN and is designated by a name. You can configure some ELANs from a router and some from a Catalyst 5000 series switch. You can configure some ELANs with unrestricted membership and some with restricted membership. You can also configure a default ELAN, which must have unrestricted membership.

To create a VLAN that spans multiple Catalyst 5000 series switches on an ATM network, you must assign the VLAN on each Catalyst 5000 series switch to the same ELAN. Enter the lane client ethernet vlan_num elan_name command to link the VLAN number with the ELAN name. You must use a router to allow communication between two or more ELANs, whether they are on the same or different Catalyst 5000 series switches.

Joining a LEC to an ELAN

The following process (illustrated in Figure 5-5) normally occurs after you enable a LEC on the ATM module in a Catalyst 5000 series switch:

1 ) The LEC requests to join an ELAN.

The LEC sets up a connection to the LECS (bidirectional, point-to-point Configure Direct VCC, link 1-7 in Figure 5-5) to find the ATM address of the LES for its ELAN.

The LEC sets up a connection to the LES for its ELAN (bidirectional, point-to-point Control Direct VCC, link 1-7 in Figure 5-5) to exchange control traffic.

The LES for the ELAN sets up a connection to the LECS to verify that the LEC is allowed to join the ELAN (bidirectional, point-to-point Server Configure VCC, link 11-12 in Figure 5-5). The LES configuration request contains the LEC MAC address, its ATM address, and the name of the ELAN. The LECS checks its database to determine whether the LEC can join that LAN, and then it uses the same VCC to inform the LES whether or not the LEC is allowed to join.

6 ) The LES allows or does not allow the LEC to join the ELAN.

7 ) If allowed, the LES adds the LEC to the unidirectional, point-to-multipoint Control Distribute VCC (link 2-8 in Figure 5-5) and confirms the join over the bidirectional, point-to-point Control Direct VCC (link 1-7 in Figure 5-5). If not allowed, the LES rejects the join over the bidirectional, point-to-point Control Direct VCC (link 1-7 in Figure 5-5).

8 ) The LEC sends LE ARP packets for the broadcast address, which is all 1s.

Sending LE ARP packets for the broadcast address returns the ATM address of the BUS. The LEC sets up the Multicast Send VCC (link 4-9 in Figure 5-5), and the BUS adds the LEC to the Multicast Forward VCC (link 5-10 in Figure 5-5) to and from the BUS.

Resolving ELAN Addressing

As communication occurs on the ELAN, each LEC dynamically builds a local LANE Address Resolution Protocol (LE ARP) table. A LEC LE ARP table can also have static, preconfigured entries. The LE ARP table maps MAC addresses to ATM addresses.

1 ) The LEC sends a LE ARP request to the LES for this ELAN (point-to-point Control Direct VCC, link 1-7 in Figure 5-5).

2 ) If the MAC address is registered with the LES, it returns the corresponding ATM address. If not, the LES forwards the LE ARP request to all LECs on the ELAN (point-to-multipoint Control Distribute VCC, link 2-8 in Figure 5-5).

3 ) Any LEC that recognizes the MAC address responds with its ATM address (point-to-point Control Direct VCC, link 1-7 in Figure 5-5).

4 ) The LES forwards the response (point-to-multipoint Control Distribute VCC, link 2-8 in Figure 5-5).

5 ) The LEC adds the MAC address-ATM address pair to its LE ARP cache.

6 ) The LEC establishes a VCC to the desired destination and transmit packets to that ATM address (bidirectional, point-to-point Data Direct VCC, link 6-6 in Figure 5-5).

Sending Multicast Traffic

When a LEC sends broadcast, multicast, or unicast traffic with an unknown address, the following process occurs:

• The LEC sends the packet to the BUS (unidirectional, point-to-point Multicast Send VCC, link 4-9 in Figure 5-5).

• The BUS floods the packet to all LECs (unidirectional, point-to-multipoint Multicast Forward VCC, link 5-10 in Figure 5-5). This VCC branches at each switch. The switch forwards such packets to multiple outputs. (The switch does not examine the MAC addresses; it simply forwards all packets it receives.)

Addressing

On a LAN, packets are addressed by the MAC-layer addresses of the destination and source stations. To provide similar functionality for LANE, MAC-layer addressing must be supported. Every LEC must have a MAC address. In addition, every LANE component (LECS, LES, BUS, and LEC) must have a unique ATM address.

In this release, all LECs on the same interface have the same automatically assigned MAC address. That MAC address is also used as the end-system identifier (ESI) part of the ATM address, as explained in the following section. Although LEC MAC addresses are not unique, all ATM addresses are unique.

Defining LANE ATM Addressing Structure

A LANE ATM address has the same syntax as an NSAP, but it is not a network-level address. It consists of the following:

Assigning ATM Addresses Automatically

Cisco provides the following method of constructing and assigning ATM and MAC addresses in a LECS database. A pool of 16 MAC addresses is assigned to each ATM module. For constructing ATM addresses, the following assignments are made to the LANE components:

• The prefix fields are the same for all LANE components in routers and the Catalyst 5000 series ATM modules; the prefix indicates the identity of the switch. You must configure the prefix value on the switch.

• The ESI field value assigned to every LEC on the interface is the first pool of MAC addresses assigned to the interface.

• The ESI field value assigned to every LES on the interface is the second pool of MAC addresses.

• The ESI field value assigned to the BUS on the interface is the third pool of MAC addresses.

• The ESI field value assigned to the LECS is the fourth pool of MAC addresses.

• The selector field value is set to the subinterface number of the LANE component--except for the LECS, which has a selector field value of 0.

Because the LANE components are defined on different subinterfaces of an ATM interface, the value of the selector field in an ATM address is different for each component. The result is a unique ATM address for each LANE component, even within the same Catalyst 5000 series switch. For more information about assigning components to subinterfaces, see the "Assigning Components to Interfaces and Subinterfaces" section later in this chapter.

For example, if the MAC addresses assigned to an interface are 0800.200C.1000 through 0800.200C.100F, the ESI part of the ATM addresses is assigned to LANE components as follows:

• Any LEC gets the ESI 0800.200c.1000.

• Any LES gets the ESI 0800.200c.1001.

• The BUS gets the ESI 0800.200c.1002.

• The LECS gets the ESI 0800.200c.1003.

Using ATM Address Templates

You can use ATM address templates in many LANE commands. These templates can assign ATM addresses to LANE components (thus overriding automatically assigned ATM addresses) or link LEC ATM addresses to ELANs, simplifying the use of LANE commands. ATM address templates are very similar to the address templates used by the International Standards Organization (ISO) connectionless network services (CLNS).

LANE ATM address templates can use two types of wildcards: an asterisk (*) to match any single character and an ellipsis (...) to match any number of leading or trailing characters.

In LANE, a prefix template explicitly matches the prefix but uses wildcards for the ESI and selector fields. An ESI template explicitly matches the ESI field but uses wildcards for the prefix and selector. Table 5-3 indicates how the values of unspecified bytes are determined when an ATM address template is used.

Assigning Components to Interfaces and Subinterfaces

The following rules apply to assigning LANE components on the major ATM interface and its subinterfaces:

• The LECS is always assigned to the major interface. Assigning any other component to the major interface is identical to assigning that component to the 0 subinterface.

• The LES and the LEC of the same ELAN can be configured on the same subinterface.

• LECs of two different ELANs cannot be configured on the same subinterface.

• Servers of two different ELANs cannot be configured on the same subinterface.

Registering ILMI Addresses

The Catalyst 5000 series switch builds its ATM address by obtaining its ATM address prefix from the ATM switch. It combines the ATM address prefix with its own MAC address and the LEC subinterface number. Once the ATM module determines its ATM address, it uses ILMI registration to register this address with the ATM switch.