The Silo Chronicles
The not so exciting adventures of a Network Engineer

It’s been awhile since I last posted so I figured I would start with a command of the day post. Today’s post is actually going to be several commands. These are commands that are not very common but I find useful when working with the Cisco Autonomous Access Points.

dot11 arp-cache [optional]
This command is entered in the global configuration mode. It enables client ARP caching on the access point. ARP caching on the access point reduces the traffic on your wireless LAN and increases client battery life by stopping ARP requests for client devices at the access point. Instead of forwarding ARP requests to client devices, the access point responds to requests on behalf of associated client devices and drops ARP requests that are not directed to clients associated to the access point. When ARP caching is optional, the access point responds on behalf of clients with IP addresses known to the access point but forwards through its radio port any ARP requests addressed to unknown clients. When the access point knows all the IP addresses for associated clients, it drops any ARP requests not directed to its clients. In its beacon, the access point includes an information element to alert client devices that they can safely ignore broadcast messages to increase battery life.

dot11 [Interface] carrier busy
This has to be one of my favorite commands for deploying new access points. This command is entered in the EXEC mode and will cause the access point to do a carrier busy test on each channel resulting in a report showing you how busy each of the channels are allowing you to select a free channel. Two things to note:

1. This will disassociate users from the access point so make sure it isn’t in production or people are aware of an outage before issuing the command.

2. To see the report you need to issue a “show log” command or if connected via console console logging enabled.

show dot11 associations
This command will show you a list of devices currently associated with the access point. You might find it useful to make this an alias on the access point.

This entry was posted on Wednesday, March 18th, 2009 at 10:37 pm and is filed under General, Tips and Tricks. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.