ATM Configuration and Troubleshooting Guide

Conﬁguring EMS High Availability over ATM

Types of Failures Managed by EMS HA-ATM

Chapter 6 99

• A Broadcast and Unknown Server (BUS), which manages broadcast

and multicast trafﬁc and the discovery of unknown destination end

systems.

The ATM adapter joins an ELAN by contacting the LECS to obtain the

ATM address of the LES and BUS for that ELAN. If the primary LAN

Emulation Services fail, the secondary LAN Emulation Services come

into operation.

Necessary Conﬁguration Conﬁgure a secondary LECS and a

secondary ELAN (LES/BUS pair), so that if any one of the LECS, LES, or

BUS fails, the LAN Emulation Services are maintained. This provides

LECS, LES, and BUS redundancy.

NOTE The conﬁguration parameters (for example, MTU Size) must be the same

for the primary and secondary LAN Emulation Services.