It's very difficult to control client roaming as this is something that the client PC decides. There is very little you can do to the AP config to affect the clients roaming behaviour. If the APs are quite close together you could try reducing the transmit power to keep the area covered by each AP as small as possible so there is minimum overlap. The only other thing (which is a bit tedious) would be to hard code each client to connect to a particular AP but this would only really work if the clients didn't move around.
It would be a good idea to do a survey and see how much overlap there is between APs at different transmit power levels, this will help you keep overlap to a minimum.
Using 1, 6 & 11 prevents interference between the APs. If you have too much overlap then clients may "flap" between APs and you will have little control of which client connects to which AP. Keeping the transmit power as low as possible will ensure that any one client (hopefully) will only "see" one AP at a time and they won't all pile onto one AP.
I was playing around with one of my APs (lwapp) and manually set the power all the way up. I was able to witness the client flapping Andrew mentions. I did notice that my radio on my Dell D600 had less issues than 2 Dell D400s at the same table. Just goes to show you that not all client radios are equal. I set the one AP back to global control and My connection was stable enough to stream music over the wireless and one of the Dell D400s worked fine, while the other still had issues.
Blame it on card drivers, service paks, phase of the moon,etc.
Both my Dell 600 & d610 are dual boot with XP & Ubuntu and I get better connectivity with Ubuntu
While at Cisco Networkers this year, they had 3 APs mounted on the same easel and had placed a few of the AP/easels around the conf center.
It seemed to work fine for the most part, but I was not privy to the config they were using.
Using 1, 6, and 11 will prevent interference between the APs as mentioned.
The hook is whether any other APs or wireless equipment within range are using any of those channels / frequencies ... they will interfere, and be interfered with, any other devices on thoses channels / frequencies.
For example, if users set up "Ad-Hoc" networking on channel 1, the AP (and all clients within range) on channel 1 will see the interference.
The other thing is that there is no way to truely "load balance" with all of the APs, regardless of the channel if they are all on the same SSID.
Depending on your circumstances, you may want to implement a "Red, Green, Blue" system where (by whatever method you choose) access is given to the users on a rotating / round-robin basis; some users are on teh "Red" net, some are on the "Green" net, some are on the "Blue" net.
Having different SSIDs per AP is the only way you can guarantee that users X ends up on network segment in a balanced load.
There are a couple different ways to cause the users to pick up their assignment automatically, but if the users are fairly static, it is probably easier in the long run to just assign the network manually(and put a color dot on the client, so when they call with a problem you can ask what color their on).
Remote areas can support all three SSIDS on one AP since the probable load is likely to be less.
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...
I have created a Powershell script to automatically add a Wireless Guest
User on Cisco WLCs. (tested on 2500 Series) The script should be
completely self explanatory. Prerequisites: Powershell SNMP Module
(Install-Module -Name SNMP) SNMP Write Access to y...