Extreme 6800 Manuale Supplementare

Part Number: 121071-00 Rev 01

1

Hitless Failover and 
Hitless Upgrade User Guide

This guide describes hitless failover and hitless upgrade, including:

T-sync is a term used to describe the hitless failover and hitless upgrade features available on the 
BlackDiamond

®

 Management Switch Module 3 (MSM-3). In simple terms, hitless failover transfers switch 

management control from the master MSM-3 to the slave MSM-3 without causing traffic to be dropped. 
Hitless upgrade allows an ExtremeWare

®

 software upgrade on a BlackDiamond 6800 series chassis 

without taking it out of service or losing traffic. 

To configure hitless failover or hitless upgrade, you must install MSM-3 modules in your BlackDiamond 
chassis; MSM64i modules do not support hitless failover or hitless upgrade. 

If you enable T-sync and normally use scripts to configure your switch, Extreme Networks recommends 
using the 

download configuration incremental

 command instead.

Causes and Behaviors of MSM Failover

This section describes the events that cause an MSM failover and the behavior of the system after 
failover occurs.

The following events cause an MSM failover:

Operator command