H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 733)

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• Primary AC recovery:
Primary AC provides a mechanism to make sure the primary AC is chosen in precedence by APs
as an active AC. When the primary AC goes down, the APs switch to connect to the standby AC.
As soon as the active AC recovers, the APs automatically connect to the primary AC again.
Figure 744 Primary AC recovery
AC 1 is the primary AC with the connection priority of 7, and it establishes a connection with the
AP. AC 2 acts as the secondary AC. If AC 1 goes down, AC 2 takes over to provide services to
AP until AC 1 recovers. Once the primary AC is reachable again, the AP automatically establishes
a connection with the primary AC. For more information about priority configuration, see
"
Configuring an AP connection priority ."
1+1 fast backup
Fast link fault detection allows two ACs in 1+1 backup to detect the failure of each other. To achieve this,
a heartbeat detection mechanism is used. When the active AC goes down, the standby AC can quickly
detect the faults and become the new active AC.
NOTE:
•
1+1 fast backup supports only tunnel backup between AC and AP to make sure when the main AC goes down,
the standby AC can quickly connect to the AP. 1+1 fast backup does not back up client information.
• Support for this feature depends on the device model. For more information, see " About the H3C Access
Controllers Web-Based Configuration Guides ."
1+N AC backup
1+N AC backup allows an AC to operate as a backup for multiple ACs. The active ACs independently
provide services for APs that connect to them, and only one standby AC provides backup service for the
active ACs. If an active AC goes down, the APs connecting to it can detect the failure quickly and make
connections to the standby AC. As soon as the active AC recovers, the APs automatically connect to the
original active AC again. This makes sure the standby AC operates as a dedicated backup for the active
ACs. 1+N AC backup delivers high reliability and saves network construction cost.