An enterprise network requires redundant, high-bandwidth connectivity between a Cisco AireOS Wireless LAN Controller (WLC) distribution port bundle and a Cisco Catalyst distribution switch. The network team decides to enable Link Aggregation (LAG) on the controller. Which TWO switch-side configurations and behaviors are mandatory for this infrastructure connection to operate correctly? (Select two.)
- The switch member ports must be statically bundled using channel-group mode on because AireOS LAG does not negotiate using dynamic protocols like LACP or PAgP.Answer
- The switch port-channel interface must be configured as an 802.1Q trunk carrying all necessary wireless client and management VLANs with matching native VLAN settings.Answer
- CThe switch interfaces must be configured with channel-group mode passive to allow the controller to initiate PAgP dynamic trunking negotiation.
- DAccess layer switch ports connected to Local mode Lightweight APs must be converted to 802.1Q trunks so client traffic can bypass the WLC bundle during high load.
Answer
The mandatory switch-side configurations are configuring member ports in static EtherChannel mode (channel-group mode on) and setting the port-channel interface as an 802.1Q trunk carrying the required VLANs with matching native VLAN configurations.
On Cisco AireOS controllers, enabling LAG aggregates all physical distribution ports into a single logical channel. Because AireOS does not support dynamic negotiation protocols (LACP or PAgP), the upstream switch member ports must be statically bound using mode on. Additionally, because multiple VLANs (management, dynamic client WLANs, AP manager) travel across this aggregate link, the port-channel interface on the Catalyst switch must be configured as an 802.1Q trunk with properly aligned native and allowed VLANs.
Step-by-Step Solution
Key Concept
Cisco AireOS WLC Link Aggregation (LAG) and Upstream Switch Trunking
Estimated Time:1m 30s