Cabletron Systems 04-0053-01 Manual De Usuario

2-6   SmartSwitch ATM User Guide

Creating an Emulated LAN

  IP Over ATM and LANE

acquire the LECS address through ILMI or use the Well Known Address as the address for the 
LECS. For details on the ATM SmartSwitch automatic addressing scheme for LANE, see 
Section 2.2.1.

As each end device registers with the LES and BUS, messages are sent to the event log of the ATM 
SmartSwitch containing the LECS. You can check connectivity by pinging between end nodes.

If configured devices fail to join the ELAN, see Chapter 4, "Routing." Section 4.3. 
Also, see Chapter 9, "Troubleshooting."

Your ELAN is now operational. Additional ELANs can be created in the same way.

While it is possible for a single ELAN on an ATM SmartSwitch to support 
multiple subnets, in general, switch performance is best (and management easiest) 
when the “One-subnet-per-ELAN” rule is observed.

2.2.1

ATM Addressing for LAN Emulation

All ATM SmartSwitches provide default formats for ATM addresses used by LAN emulation entities (local client, 
LECS, LES, and BUS). The SmartSwitch 2500 family of ATM switches and the SmartSwitch 6500 use different 
methods for constructing these default addresses.

SmartSwitch 2500 Family Default LANE Addressing

The 

 is constructed from:

39 + nine zero bytes + last three bytes of CPU MAC address

For example, the chassis MAC address = 

00:20:14:41:80

, 

then 

default netprefix = 

39:00:00:00:00:00:00:00:00:00:14:41:80

The 

 address is constructed from:

netprefix + CPU MAC address with last byte summed with the client number + zero selector byte

For example

netprefix = 

39:00:00:00:00:00:00:00:00:00:14:41:80

CPU MAC address = 

00:20:D4:14:41:80

, 

client number = 

5

then,

client five’s default ATM address = 

39:00:00:00:00:00:00:00:00:00:14:41:80:00:20:D4:14:41:85:00