3Com Switch 8800 Advanced Software V5 Configuration Guide

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HIGH AVAILABILITY CONFIGURATION
When configuring HA, go to these sections for information you are interested in:
■ “Introduction to HA” on page 1113
■ “Configuring HA” on page 1113
■ “Displaying and Maintaining HA” on page 1114
■ “HA Configuration Example” on page 1114
Introduction to HA High Availability (HA for short) feature can be used to achieve a higher degree of
system availability. Devices supporting HA are normally equipped with two
Switching and Routing Process Units (Fabric for short), with one being the active
card that works under master mode and the other being the standby card that
works under slave mode. With the synchronization function standby card can
work under the same system configuration. Thus, in the event of an active card
failure, the standby card will immediately switch over to function as an active card
(referred to as switchover hereafter), ensuring that the device works properly and
its configuration is synchronized with that of the active card.
Switchover occurs in the following cases:
■ Active card failure
■ The active card is plugged out
■ SNMP
■ Manual switchover
A switchover takes place in the following order in the event of an active card
failure:
1 The standby card automatically connects and controls system bus while the
original active card disconnects from it.
2 The original standby card becomes the new active card whereas the original active
card automatically reboots and functions as the new standby card.
We discuss switchover through user command line in this chapter.
Configuring HA
To do... Use the command... Remarks
Enter system view system-view -
Enable the manual switchover
between the active card and
standby card
slave switchover { enable |
disable }
Optional
Enabled by default