Using Link Aggregation; Using Multiple Ap-Manager Interfaces - Cisco OL-8335-02 Configuration Manual

Chapter 3 Configuring Ports and Interfaces
The following factors should help you decide which method to use if your controller is set for Layer 3
operation:
•
•

Using Link Aggregation

See the
enabling link aggregation.
Link aggregation is the only method that can be used for the Cisco WiSM controllers.
Note

Using Multiple AP-Manager Interfaces

This method can be used only with Cisco 4400 series stand-alone controllers.
Note
When you create two or more AP-manager interfaces, each one is mapped to a different port (see
Figure
port 2, AP-manager interface 3 is on port 3, and AP-manager interface 4 is on port 4. In addition, all
AP-manager interfaces must be on the same VLAN or IP subnet, and they may or may not be on the same
VLAN or IP subnet as the management interface.
You must assign an AP-manager interface to each port on the controller.
Note
Before an access point joins a controller, it sends out a discovery request. From the discovery response
that it receives, the access point can tell the number of AP-manager interfaces on the controller and the
number of access points on each AP-manager interface. The access point generally joins the AP-manager
with the least number of access points. In this way, the access point load is dynamically distributed
across the multiple AP-manager interfaces.
Note Access points may not be distributed completely evenly across all of the AP-manager interfaces, but a
certain level of load balancing occurs.
OL-8335-02
With link aggregation, all of the controller ports need to connect to the same neighbor switch. If the
neighbor switch goes down, the controller loses connectivity.
With multiple AP-manager interfaces, you can connect your ports to different neighbor devices. If
one of the neighbor switches goes down, the controller still has connectivity. However, using
multiple AP-manager interfaces presents certain challenges (as discussed in the
AP-Manager Interfaces" section below) when port redundancy is a concern.
"Enabling Link Aggregation" section on page 3-27
3-14). The ports should be configured in sequential order such that AP-manager interface 2 is on
Configuring a 4400 Series Controller to Support More Than 48 Access Points
for more information and instructions on
Cisco Wireless LAN Controller Configuration Guide
"Using Multiple
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