Chapter 5
Troubleshooting
Guidelines for Using the Access Points
You should keep these guidelines in mind when you use the access points:
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Important Notes
Convergence Delays
During deployment, the access points can experience convergence delays due to various causes. The
following list identifies some operating conditions that can cause convergence delays:
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OL-32138-01
The access point only supports Layer 3 CAPWAP communications with the controllers.
In Layer 3 operation, the access point and the controller can be on the same or different subnets. The
access point communicates with the controller using standard IP packets. A Layer 3 access point on
a different subnet than the controller requires a DHCP server on the access point subnet and a route
to the controller. The route to the controller must have destination UDP ports 12222 and 12223 open
for CAPWAP communications. The route to the primary, secondary, and tertiary controllers must
allow IP packet fragments.
Before deploying your access points, ensure that the following has been done:
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Your controllers are connected to switch ports that are configured as trunk ports.
Your access points are connected to switch ports that are configured as untagged access ports.
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A DHCP server is reachable by your access points and has been configured with Option 43.
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Option 43 provides the IP addresses of the management interfaces of your controllers. Typically,
a DHCP server can be configured on a Cisco switch.
Optionally, a DNS server can be configured to enable CISCO-CAPWAP-CONTROLLER. Use
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local domain to resolve to the IP address of the management interface of your controller.
Your controllers are configured and reachable by the access points.
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Your controllers are configured with the access point MAC addresses and the MAC filter list is
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enabled.
Your switch must forward DHCP requests.
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After the access points are associated to the controller, you should change the bridge group name
(BGN) from the default value. With the default BGN, the mesh access points (MAPs) can potentially
try to connect with other mesh networks and slow down the convergence of the network.
A root access point (RAP) attempts to connect to a controller using any of the wired ports (cable,
fiber-optic, PoE-in). If the wired ports are operational, the RAP can potentially spend several
minutes on each port prior to connecting to a controller.
If a RAP is unable to connect to a controller over the wired ports, it attempts to connect using the
wireless network. This results in additional delays when multiple potential wireless paths are
available.
If a MAP is unable to connect to a RAP using a wireless connection, it then attempts to connect using
any available wired port. The access point can potentially spend several minutes for each connection
method, before attempting the wireless network again.
Cisco Aironet 1570 Series Outdoor Access Point Hardware Installation Guide
Guidelines for Using the Access Points
5-3