Rockwell Automation 1783-WAPxxx Stratix 5100 Wireless Access Point User Manual - Manual (Page 229)

Rockwell Automation Publication 1783-UM006A-EN-P - May 2014 229
Administering the WAP Access Chapter 6
Configuring Client ARP
Caching You can configure the wireless device to maintain an ARP cache for associated
client devices. Maintaining an ARP cache on the wireless device reduces the
traffic load on your wireless LAN. ARP caching is disabled by default.
ARP caching on the wireless device reduces the traffic on your wireless LAN by
stopping ARP requests for client devices at the wireless device. Instead of
forwarding ARP requests to client devices, the wireless device responds to
requests on behalf of associated client devices.
When ARP caching is disabled, the wireless device forwards all ARP requests
through the radio port to associated clients, and the client responds. When ARP
caching is enabled, the wireless device responds to ARP requests for associated
clients and does not forward requests to clients. When the wireless device receives
an ARP request for an IP address not in the cache, the wireless device drops the
request and does not forward it. In its beacon, the wireless device includes an
information element to alert client devices that they can safely ignore broadcast
messages to increase battery life.
Optional ARP Caching
If a client device is associated to an access point in not a Cisco device and is not
passing data, the wireless device does not know the client IP address. If this
situation occurs frequently on your wireless LAN, you can enable optional ARP
caching. When ARP caching is optional, the wireless device responds on behalf of
clients with IP addresses known to the wireless device but forwards out its radio
port any ARP requests addressed to unknown clients. When the wireless device
learns the IP addresses for all associated clients, it drops ARP requests not
directed to its associated clients.
Configuring ARP Caching
Beginning in privileged EXEC mode, follow these steps to configure the wireless
device to maintain an ARP cache for associated clients:
1. Enter global configuration mode.
configure terminal
2. Enable ARP caching on the wireless device.
• (Optional) Use the
optional keyword to enable ARP caching only
for the client devices whose IP addresses are known to the wireless
device.
dot11 arp-cache [ optional ]
3. Return to privileged EXEC mode.
end
4. Verify your entries.
show running-config