Cisco Cisco Aironet 1522 Lightweight Outdoor Mesh Access Point 디자인 가이드

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Cisco Aironet 1520, 1130, 1240 Series Wireless Mesh Access Points, Design and Deployment Guide, Release 6.0
OL-20213-01
  Connecting the Cisco 1520 Series Mesh Access Point to Your Network
Configuring Backup Controllers
A single controller at a centralized location can act as a backup for mesh access points when they lose 
connectivity with the primary controller in the local region. Centralized and regional controllers need 
not be in the same mobility group. Using the controller GUI or CLI, you can specify the IP addresses of 
the backup controllers, which allows the mesh access points to fail over to controllers outside of the 
mobility group.
You can also configure primary and secondary backup controllers (which are used if primary, secondary, 
or tertiary controllers are not specified or are not responsive) for all access points connected to the 
controller as well as various timers, including the heartbeat timer and discovery request timers.
Note
The fast heartbeat timer is not supported on mesh access points. The fast heartbeat timer is only 
configured on access points in local and hybrid-REAP modes.
The mesh access point maintains a list of backup controllers and periodically sends primary discovery 
requests to each entry on the list. When the mesh access point receives a new discovery response from 
a controller, the backup controller list is updated. Any controller that fails to respond to two consecutive 
primary discovery requests is removed from the list. If the mesh access point’s local controller fails, it 
chooses an available controller from the backup controller list in this order: primary, secondary, tertiary, 
primary backup, secondary backup. The mesh access point waits for a discovery response from the first 
available controller in the backup list and joins the controller if it receives a response within the time 
configured for the primary discovery request timer. If the time limit is reached, the mesh access point 
assumes that the controller cannot be joined and waits for a discovery response from the next available 
controller in the list.
Note
When a mesh access point’s primary controller comes back online, the mesh access point disassociates 
from the backup controller and reconnects to its primary controller. The mesh access point falls back to 
its primary controller and not to any secondary controller for which it is configured. For example, if a 
mesh access point is configured with primary, secondary, and tertiary controllers, it fails over to the 
tertiary controller when the primary and secondary controllers become unresponsive and waits for the 
primary controller to come back online so that it can fall back to the primary controller. The mesh access 
point does not fall back from the tertiary controller to the secondary controller if the secondary controller 
comes back online; it stays connected to the tertiary controller until the primary controller comes back 
up.
Note
If you inadvertently configure a controller that is running software release 6.0 with a failover controller 
that is running a different software release (such as 4.2, 5.0, 5.1, or 5.2), the mesh access point might 
take a long time to join the failover controller because the mesh access point starts the discovery process 
in LWAPP and then changes to CAPWAP discovery.
Using the GUI to Configure Backup Controllers
Using the controller GUI, follow these steps to configure primary, secondary, and tertiary controllers for 
a specific mesh access point and to configure primary and secondary backup controllers for all mesh 
access points.
Step 1
Click Wireless > Access Points Global Configuration to open the Global Configuration window. 
(See