Roaming WLAN clients between different switches

[peter.haynes]

I am currently designing a Wireless solution for a customer in a fairly large network. It is not reasonable to plug all access points into one physical switch in their network. Are there any guidelines for configuring switches to allow roaming for wireless users? Basically I am concerned with the MAC of the wireless client apearing on different switches and not getting updated in the ARP or CAM table quick enough to keep the wireless link / application working when the user roams. The speed of roaming may be extremely quick as the wireless client will be a bar-code reader attached to a forklift in a large "open air" warehouse / storage yard.

Thanks for any help,

Peter

[bmcmurdo]

As long as the switches are in the same L2 doamin this should not be a problem.

The first thing a Cisco AP does when it gets a reassociation is send a MAC layer multicast out on the ethernet with the source-IP address of the reassociating client. The purpose of this is to update the CAM tables of any upstream switches.

[peter.haynes]

Just a silly question.... is there any public info on how the roaming works ie what multicast address it sends to (just for nerd value really) and how the passover between the APs works. I've done a bit of a search and haven't come up with much.

Rgds,

Peter

[bmcmurdo]

until 802.11f is reatified, vendors Inter Access Point Protocols are all propriatary.

I do not believe Cisco has published any documentation on how ours works.

Cheers,

Bruce

[peter.haynes]

Bruce,

Thanks for the info.

Rgds,

Peter

[jmagnusson]

here is a link thta helped me understand that and much much more about wireless and WLAN deployments..

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns178/c649/ccmigration_09186a00800d67eb.pdf

[peter.haynes]

Thanks for the Document. That is exactly what I was looking for.

Rgds,

Peter