Summary: If Cisco APs could talk to each other they would use NDP, Neighbor Discovery Protocol. NDP is important to Cisco RRM. It feeds a lot of the algorithms within RRM.<br> The purpose of Cisco NDP is to allow APs to build a “map” of their locations in relation to each other. Every 180 seconds an AP will send a neighbor discovery packet over the air to a multicast address of 01:0B:85:00:00:00 from each channel.<br> NDP packets are sent at the highest transmit power and at the lowest data rate supported by the transmitting channel.<br> In terms of configuration, we are provided with three options:<br> <br> * Channel Scan Interval – default is 180 seconds<br> * Neighbor Packet Frequency – default is 180 seconds<br> * Neighbor Timeout Factor – default is a value of 5<br> <br> You can find these options in the WLC GUI:<br> Wireless > 802.11a/n/ac or 802.11b/g/n > RRM > General<br> Debug commands used to verify NDP<br> (Cisco Controller)> show ap auto-rf 802.11a AP1<br> Nearby APs<br> AP 00:3a:7d:44:44:44 slot 1.................. -23 dBm on 36 20MHz (192.168.1.5) AP4<br> AP 58:bc:27:33:33:33 slot 1.................. -18 dBm on 100 20MHz (192.168.1.5) AP3<br> AP 58:bc:27:22:22:22 slot 1.................. -40 dBm on 44 20MHz (192.168.1.5) AP2<br> AP1#debug capwap rm measurements<br> CAPWAP RM Measurements display debugging is on<br> *Aug 23 18:17:46.016: CAPWAP_RM: Timer expiry<br> *Aug 23 18:17:46.016: CAPWAP_RM: Neighbor interval timer expired, slot 1, band 0<br> *Aug 23 18:17:46.016: CAPWAP_RM: Triggering neighbor request on ch index: 2<br> *Aug 23 18:17:46.016: CAPWAP_RM: Sending neighbor packet #2 on channel 44 with power 1 slot 1<br> *Aug 23 18:17:46.016: CAPWAP_RM: Scheduling next neighbor request on ch index: 3<br> *Aug 23 18:17:46.230: CAPWAP_RM: Notification for Request id: 4044, slot: 1, status 1<br> *Aug 23 18:17:46.230: CAPWAP_RM: Neighbor packet sent successfully on 44<br> *Aug 23 18:17:46.233: CAPWAP_RM: Notification for Request id: 4044, slot: 1, status 1<br> *Aug 23 18:17:46.233: CAPWAP_RM: Neighbor packet sent successfully on 44<br> *Aug 23 18:17:49.017: CAPWAP_RM: Timer expiry<br> *Aug 23 18:17:49.017: CAPWAP_RM: Neighbor interval timer expired, slot 1, band 0<br> *Aug 23 18:17:49.017: CAPWAP_RM: Triggering neighbor request on ch index: 3<br> *Aug 23 18:17:49.017: CAPWAP_RM: Sending neighbor packet #3 on channel 48 with power 1 slot 1<br> *Aug 23 18:17:49.017: CAPWAP_RM: Scheduling next neighbor request on ch index: 4<br> *Aug 23 18:17:49.159: CAPWAP_RM: Notification for Request id: 4048, slot: 1, status 1<br> *Aug 23 18:17:49.159: CAPWAP_RM: Neighbor packet sent successfully on 48<br> *Aug 23 18:17:49.162: CAPWAP_RM: Notification for Request id: 4048, slot: 1, status 1<br> *Aug 23 18:17:49.162: CAPWAP_RM: Neighbor packet sent successfully on 48<br> AP1#debug capwap rm neighbor<br> CAPWAP RM Neighbor display debugging is on<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: Pak size 104 from 58bc.27xx.xxxx, interface - 1<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: Updating existing neighbor 58bc.27xx.xxxx(1), rssi -35 on channel: 161 with encryption: 0<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: Configured Antennas: 2, PA_POWER: 17, TPO_CONTRIBUTION: 3, Total NDP Power: 20<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: Neighbor update 58bc.27xx.xxxx(avg -36), new rssi -35, channel 161<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: NDP-TLV: Received ndp-tlv payload<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: NDP: copy TLV data to neighbor<br> *Aug 23 18:31:33.529: LWAPP NEIGHBOR: NDP Rx: From 58bc.27xx.xxxx RSSI [raw:norm:avg]=[-35:-35:-36] [Neigh Srv Chan: Neigh Off Chan : NDP Pwr]=[161:157:20 dB] Rcv Ch Max Pwr [20 dB]<br> *Aug 23 18:31:33.532: LWAPP NEIGHBOR: Pak size 76 from 58bc.27xx.xxxx, interface - 1<br> *Aug 23 18:31:33.532: LWAPP NEIGHBOR: Updating existing neighbor 58bc.27xx.xxxx(1),
