Cisco Systems 3.2 manual Link Aggregation Guidelines

Chapter 3 Configuring Ports and Interfaces

Enabling Link Aggregation

When configuring bundled ports, you may want to consider spanning modules with your port channel when you connect to a modular switch such as the Catalyst 6500. This practice provides protection in the case of a module failure. Figure 3-12illustrates a scenario where a 4402-50 controller is connected to a Catalyst 6500 with gigabit modules in slots 2 and 3. The controller’s port 1 is connected to gigabit interface 3/1, and the controller’s port 2 is connected to gigabit interface 2/1 on the Catalyst 6500. On the Catalyst switch, the two interfaces are assigned to the same channel group.

Figure 3-12 Link Aggregation with Catalyst 6500 Neighbor Switch

Link Aggregation Guidelines

Keep these guidelines in mind when using LAG:

•You cannot configure the controller’s ports into separate LAG groups. Only one LAG group is supported per controller. Therefore, you can connect a controller in LAG mode to only one neighbor device.

•When LAG is enabled, any change to the LAG configuration requires a controller reboot.

•When you enable LAG, you can configure only one AP-manager interface because only one logical port is needed.

•When you enable LAG, all dynamic AP-manager interfaces and untagged interfaces are deleted, and all WLANs are disabled and mapped to the management interface.

•When you enable LAG, you cannot create interfaces with a primary port other than 29.

•When you enable LAG, all ports participate in LAG by default. Therefore, you must configure LAG for all of the connected ports in the neighbor switch.

•When you enable LAG, port mirroring is not supported.

•Make sure the port-channel on the switch is configured for the IEEE standard Link Aggregation Control Protocol (LACP), not the Cisco proprietary Port Aggregation Protocol (PAgP).

•When you disable LAG, you must configure primary and secondary ports for all interfaces.

•When you disable LAG, you must assign an AP-manager interface to each port on the controller.

Cisco Wireless LAN Controller Configuration Guide

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