Note For more software configuration information about LANE, refer to the ATM Switch
Router Software Configuration Guide. Refer to the ATM Switch Router Command
Reference publication for command syntax.
Understanding LANE on ATM
LANE is a protocol that allows devices attached to traditional LANs (such as Ethernet and Token Ring) to connect to ATM networks. That is, LANE allows legacy LAN users to take advantage of the benefits of ATM without modifying end station hardware or software.
LANE services provide connectivity between ATM-attached devices and LAN-attached devices. Two primary applications of LANE follow:
Connectivity between LAN-attached stations across a high-speed ATM transport backbone.
Connectivity between ATM-attached hosts and LAN-attached hosts. Centralized hosts with high-speed ATM port adapters provide services (such as Domain Name Service [DNS]) to traditional LAN-attached devices.
Understanding LANE Components
A single emulated LAN (ELAN) includes the following components:
LANE client (LEC)—A software client that resides in an end station (such as a workstation, LAN switch, or router). The LEC performs data forwarding and receiving, address resolution, and other control functions for a single endpoint in a single ELAN. A router or switch can have multiple LANE clients, each connecting with different ELANs. The LANE client registers its MAC and ATM address with the LES.
LANE configuration server (LECS)—A server that assigns individual LECs to particular ELANs by providing to the LECs the ATM address of the LES. The LECS maintains a database of ELAN names and the corresponding addresses of the LESs. A LECS can serve multiple ELANs. One LECS must be configured for each LANE cloud.
Note The LECS is also used for security by restricting ELAN membership to certain
LECs, based on their MAC addresses.
LANE server (LES)—A server that registers LECs to join the ELAN. In LANE 1.0, without Simple Server Redundancy Protocol (SSRP), each ELAN has only one Cisco LES, which handles LAN Emulation Address Resolution Protocol (LE_ARP) requests.
Broadcast-and-unknown server (BUS)—A server that floods unknown destination addresses and forwards multicast and broadcast traffic to clients within an ELAN. In LANE 1.0 without SSRP, one Cisco BUS exists per ELAN.
Implementing LANE
The following sections describe specific information and considerations you might need to consider prior to LANE implementation:
The ATM switch router supports both Ethernet and Token Ring LANE. This chapter describes only Ethernet configuration information. For Token Ring configuration information, refer to the ATM Switch Router Software Configuration Guide.
Addressing
On a LAN, packets are addressed by the MAC-layer address of the destination and source stations. To provide similar functionality for LANE, every LANE client must have a MAC address. In addition, every LANE component (LES, LEC, BUS, and LECS) must have a unique ATM address.
All LANE clients on the same interface have the same automatically assigned MAC address, which is also used as the end-system identifier (ESI) part of the ATM address. Although client MAC addresses are not unique, all ATM addresses are unique.
Assigning Components to Interfaces and Subinterfaces
The following rules apply to assigning LANE components to the major ATM interface and its subinterfaces:
The LECS always runs on the major ATM interface.
If you assign any other component to the major interface, it is identical to assigning that component to the 0 subinterface.
Configure the LES/BUS and the LEC of the same ELAN on the same subinterface.
You cannot configure LECs of two different ELANs on the same subinterface.
You cannot configure LESs/BUSs of two different ELANs on the same subinterface.
Note On the ATM switch router, you can configure LAN components only on the
processor card (CPU) interface or on one of its subinterfaces.
Configuring LANE Router and LAN Switch Requirements
You must manually configure QSAAL and ILMI signaling PVCs on routers and edge LAN switches to run LANE.
Note These PVCs are configured automatically on the ATM switch router.
At least one ATM switch router is required to run LANE. For example, you cannot run LANE on routers connected back-to-back.
Configuring a LEC
This section describes how to configure a LANE client connection from a remote ATM switch router to the processor card (CPU) of a local switch. This connection allows you to configure the ATM switch router remotely.
Note This connection is for switch management only.
Take these steps:
Step
Command
Purpose
1
Switch> enable
Switch#
Enter privileged EXEC mode.
2
Switch# configure terminal
Switch(config)#
Enter global configuration mode.
3
Switch(config)# interface atm 0[.subinterface]
Switch(config-if)#
Select the processor card (CPU) subinterface.
Note We recommend that you configure LECs on subinterfaces (atm 0.1), not main interfaces (atm 0).
4
Switch(config-if)# lane client-atm-addressatm-address-template
Specify an ATM address (and override the automatic ATM address assigned to the LANE client).
5
Switch(config-if)# lane clientethernetelan-name
Configure a LANE client on the specified subinterface.
You must configure the ATM address of the LECS on the ATM switch router.
Configuring the ATM Address of the LECS
The ATM switch router comes with a default unique prefix. To see the default prefix, enter the show lane default atm address command. You can use the default prefix or assign a new one. If you want to use the default prefix, skip this section and proceed to the next section.
This section describes how to change the default prefix and configure a new one. All attached LANE entities use the prefix to create their own ATM network service access point (NSAP) addresses.
Take these steps:
Step
Command
Purpose
1
Switch> enable
Switch#
Enter privileged EXEC mode.
2
Switch# configure terminal
Switch(config)#
Enter global configuration mode.
3
Switch(config)# interface atm 0
Select the ATM interface on the processor card (CPU).
4
Switch(config)# atm lecs-addresslecsaddress
Configure the LECS address on the ATM switch router.
Configure a redundant LECS address and sequence number for the entire switch. The sequence number specifies the order of the address in the LECS address table. If you do not specify a sequence number, the addresses are used in the order entered.
6
Switch(config)# atm addressaddress
Configure a new ATM address.
7
Switch(config)# no atm addressaddress
Disable the old default ATM address.
Note Enter the show atm addresses command to display the default ATM addresses.
Specify redundant LES/BUSs, or simple server replication. Enter the command for each LES address for the same ELAN. The index determines the priority. Zero (0) is the highest priority.
In Cisco's implementation of LANE, the LES and BUS are treated as one LANE component. You configure the LES and BUS together as one component (the LES/BUS), instead of two separate LANE components.
Switch(config-if)# lane server-busethernetelan-name1
Enable a LES/BUS for the first ELAN.
5
Switch(config-if)#ip addressaddress mask
Assign an IP address to the subinterface.
6
Switch(config-if)# end
Switch#
Return to privileged EXEC mode.
LANE Configuration Examples
The following examples show how to configure one Cisco 7505 router, one ATM switch router, and one Catalyst 5500 switch for a single ELAN.
The ATM switch router contains the LECS, LES, BUS, and a LEC. The remaining router and Catalyst 5500 switch each contain an LEC for the ELAN. This example uses all LANE default settings. For example, it does not explicitly set ATM addresses for the different LANE components that are collocated on the ATM switch router. Membership in this LAN is not restricted (see Figure 4-1).
Figure 4-1 Single ELAN Example Network
ATM Switch Router
ATM_Switch# show lane default-atm-addresses
interface ATM0:
LANE Client: 47.00918100000000E04FACB401.00E04FACB402.**
LANE Server: 47.00918100000000E04FACB401.00E04FACB403.**
LANE Bus: 47.00918100000000E04FACB401.00E04FACB404.**
LANE Config Server: 47.00918100000000E04FACB401.00E04FACB405.00
note: ** is the subinterface number byte in hex
ATM_Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
The following example shows how to use the show lane and ping commands to confirm the connection between the ATM switch router, routers, and LAN switches:
ATM Switch Router
Switch# show lane
LE Config Server ATM0 config table: eng_dbase
Admin: up State: operational
LECS Mastership State: active master
list of global LECS addresses (31 seconds to update):
47.00918100000000E04FACB401.00E04FACB405.00 <-------- me
ATM Address of this LECS: 47.00918100000000E04FACB401.00E04FACB405.00 (auto)
vcd rxCnt txCnt callingParty
82 2 2 47.00918100000000E04FACB401.00E04FACB403.01 LES eng_elan 0 active
cumulative total number of unrecognized packets received so far: 0
cumulative total number of config requests received so far: 4
cumulative total number of config failures so far: 0
LE Server ATM0.1 ELAN name: eng_elan Admin: up State: operational
