Information About Neighbor Discovery Protocol Mode
In Cisco Catalyst 9124AX Outdoor Access Points, the Neighbor Discovery Protocol (NDP) packets are transmitted either ON-channel on the serving radio or OFF-channel on the RF ASIC conventional radio. The controller supports a knob to select the NDP mode for Cisco Catalyst 9124AX Outdoor APs based on the deployment needs. In Cisco IOS XE Bengaluru 17.5.1 Release, Cisco Catalyst 9124AX Outdoor APs support both On-Channel and Off-Channel NDP.
The AP advertises the following NDP mode capabilities while joining the controller:
On-Channel (Serving channel)
Off-Channel (RF ASIC radio)
Both (Serving channel and RF ASIC radio)
The supported values for NDP mode are AUTO and Off-Channel. By default, the NDP mode is set to AUTO.
If the configured NDP mode is AUTO, the access point will determine which NDP mode is to be used. The Cisco Catalyst 9124AX Outdoor Access Point will use On-Channel when the controller is configured for AUTO NDP mode. If the NDP mode configured is Off-Channel, all the access points will use Off-Channel for NDP mode.
You must configure the controller NDP mode to Off-channel in order to support brownfield deployment. A brownfield deployment refers to the mixed deployment of Cisco Catalyst 9124AX with other access points that do not support RF ASIC conventional radio. Access points that supports RF ASIC conventional radio are Cisco Catalyst 9120 Access Points, Cisco Catalyst 9130 Access Points, and Cisco Catalyst 9124 Access Points.