Proxy arp -wlc

[bluesea2010]

Hi, 

Why do we need proxy arp in wirless controller ?. Does proxy arp causes duplicate address in dhcp server ?

Thanks

[mohanak]

Wireless LAN controllers currently act as a proxy for ARP requests. Upon receiving an ARP request, the controller responds with an ARP response instead of passing the request directly to the client. This scenario has two advantages:

• The upstream device that sends out the ARP request to the client will not know where the client is located.

• Power for battery-operated devices such as mobile phones and printers is preserved because they do not have to respond to every ARP requests.

Since the wireless controller does not have any IP related information about passive clients, it cannot respond to any ARP requests. The current behavior does not allow the transfer of ARP requests to passive clients. Any application that tries to access a passive client will fail.

[Prakash Parvathala]

Why do we need proxy arp in wirless controller ?.

When proxy ARP is enabled, this allows the WLAN ontroller to answer any ARP requests on behalf of the client. If not known, it will forward the ARP request over the air at DTIM.

WLC does proxy arp for all of its wireless client using its management interface, for no arp it broadcasts the packet to upstream which in turn forwarded to wired interface for that vlan.

To set the ARP proxy ARP mode, use the config network arpunicast command.

config network arpunicast {enable | disable}

[abwahid]

Hi,

Go through the below link to understand need of proxy arp.

http://mrncciew.com/2013/03/13/passive-clients/