9130 CDP on Radio interfaces

[Gehrig_W]

Hello Cisco WLAN-experts,

during startup of a new 9130AXI-AP I noticed that CDP is active on two of three radio interfaces by default.

What is the benefit of running CDP on radio interfaces on this WLAN AP working on a 9800-80-WLC ?

Please check and come  back with information.

Thank You in advance

Wini

[Flavio Miranda · Accepted solution]

Hi

 CDP (Cisco Discovery Protocol) is not required on Radios interfaces. CDP is used on the Wired interface to discovery devices and map the network and negociate power with PoE interface.

 On the Radio interface there is another protocol called "Neighbor Discovery Protocol" enable by default. NDP is similar to CDP but used for Wi-Fi porpuse.

 You can/should disable CDP on radios interface for better performance.

[Gehrig_W]

Hello Flavio,

thank You very much for this information.

I will disable CDP on the radio interfaces of this new Cisco AP model therefore, like we did in the past for 3800- and 2700-series also.

NDP is not mentioned at all in the help-file of the 5520-WLC-series, but the RRM-whitepaper explains a lot.

The Config-Guide 8.5 contains the Config-command naming it precisely NDP :

To configure RRM NDP using the controller CLI, enter this command: config advanced 802.11{a|b} monitor ndp-mode {protected | transparent}

The Version 8.5 Config-Guide contains also the show-command, but speaking in erroneous way "To configure".

To configure RRM NDP using the controller CLI, enter this command:

show advanced 802.11{a|b} monitor

The output also does not speak of NDP, but calls it Neighbor Discovery only.

(WLC-5520-1) >show advanced 802.11b monitor

Default 802.11b AP monitoring
802.11b Monitor Mode........................... enable
802.11b Monitor Channels....................... DCA channels
802.11b RRM Neighbor Discovery Type............ Transparent
802.11b RRM Neighbor RSSI Normalization........ Enabled
802.11b AP Coverage Interval................... 90 seconds
802.11b AP Load Interval....................... 60 seconds
802.11b AP Monitor Measurement Interval........ 180 seconds
802.11b AP Neighbor Timeout Factor............. 20
802.11b AP Report Measurement Interval......... 180 seconds

Thank You for Your clarification and good advise.

Kind  regards

Wini