H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 577)

561
2. Using fast link fault detection, you can configure 1+1 fast backup (see " 1+1 fast backup ") to
provide uninterrupted services.
3. 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 592 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 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 in time. 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:
Support for the 1+1 fast backup feature may vary depending on your device model. For more
information, see "Feature matrixes."
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 the 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 greatly.