Correcting High CPU Overhead and Network Utilization Issue with Multicast on Cisco Controller

B.

When multicast is enabled on a wireless controller with a large number of access points, it can lead to high CPU usage on the controller and increased network utilization. This is because multicast traffic needs to be forwarded to all of the connected APs, which can result in a lot of unnecessary network traffic.

To address this issue, the controller can be configured to use IGMP snooping. IGMP (Internet Group Management Protocol) is a protocol that is used by hosts to report their multicast group memberships to nearby multicast routers. IGMP snooping is a feature that allows the controller to listen in on these IGMP messages and use the information to only forward multicast traffic to the APs that have requested it. This can significantly reduce the amount of unnecessary multicast traffic on the network and reduce the load on the controller.

Therefore, the correct answer to this question is A. controller IGMP snooping. The other options (B, C, and D) do not address the root cause of the issue and may even exacerbate the problem by increasing the amount of multicast traffic on the network.

Option B, multicast AP multicast mode, refers to a feature that allows APs to multicast packets directly to each other without involving the controller. While this can be useful for certain applications, it does not address the issue of excessive multicast traffic on the network.

Option C, broadcast forwarding, is a feature that allows the controller to forward broadcast packets (e.g. DHCP requests) to all connected APs. While this can be useful in some scenarios, it does not address the issue of excessive multicast traffic on the network.

Option D, unicast AP multicast mode, is not a valid feature and does not address the issue at hand.