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For you Cisco wireless folks out there, I'm curious if you have any thoughts/recommendations on "Client Load Balancing" in your Dorms/Residence Halls. I'm chasing a bunch of reports of wireless users being kicked off the network for no apparent reason. They are able to rejoin right away, but it's happening enough times that they've given up Skyping or other streaming Internet-based applications. The interesting thing is that we are not getting reports of this out in the Academic buildings but it occurred to me that our design is such that those APs join to a pair of WiSM2s while our Residence Hall APs join to a pair of 5508s. On the WiSM2s we have NOT enabled Client Load Balancing, but we did on the 5508s. The rationale we used was that if a wireless client had 2 APs within decent range, Client Load Balancing would help to keep the clients from all associating to one of the two APs. Now I'm wondering if something isn't working quite right and the result is users getting bounced. I have a TAC case open and so far the engineer has come back with upping the "Client user idle timeout" from 5 minutes to 1 hr. I'm not convinced that will help, but also curious if folks have thoughts on that recommendation. Thanks, -dan -- Dan Brisson Network Engineer University of Vermont (Ph) 802.656.8111 dbrisson@uvm.edu ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.

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Out of curiosity, have you looked to see if any of the affected clients have IPv6 enabled (assuming that it's not an IPv6 network)? -Lee Badman
Lee, We do have v6 enabled for our main campus SSID. We actually did that last year over winter break and found that it didn't cause any issues. At least none that we could attribute. Thanks, -dan Dan Brisson Network Engineer University of Vermont (Ph) 802.656.8111 dbrisson@uvm.edu On 10/23/2013 9:35 AM, Lee H Badman wrote: > Out of curiosity, have you looked to see if any of the affected clients have IPv6 enabled (assuming that it's not an IPv6 network)? > > -Lee Badman > >
I should have also mentioned that we are on 7.4.110 for all of our controllers. -dan Dan Brisson Network Engineer University of Vermont (Ph) 802.656.8111 dbrisson@uvm.edu On 10/23/2013 9:40 AM, Dan Brisson wrote: > Lee, > > We do have v6 enabled for our main campus SSID. We actually did that > last year over winter break and found that it didn't cause any > issues. At least none that we could attribute. > > Thanks, > > -dan > > > Dan Brisson > Network Engineer > University of Vermont > (Ph) 802.656.8111 > dbrisson@uvm.edu > > On 10/23/2013 9:35 AM, Lee H Badman wrote: >> Out of curiosity, have you looked to see if any of the affected >> clients have IPv6 enabled (assuming that it's not an IPv6 network)? >> >> -Lee Badman >> >>
Message from dannyeaton@rice.edu

We had some clients (specifically running on Linux MINT) that had issues with either/both the Load Balancing or Band Select, so for the controller hosting the APs in the Computer Science building, we had to disable both options. (Similar description to your issue, where the client would constantly report being kicked off, and then rejoin. However, in MINT it's problematic to constantly rejoin the SSID). ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
I had similar issues in our Residence Halls on 7.4, but Cisco and support forums advised me against using Client Load Balancing and Client Band Select.  I made two changes and I haven't had a report of this since.  First, I reduced the amount of APs I had in the Vlans.  The second thing was enabling bandwidth constraints on the SSIDs.  What model APs are you using?  How many APs per Vlan?  Are you using any QoS? Before upgrading our APs we also had these issues, but since upgrading them to the 1600/2600/3600 series the fixes I mentioned worked.

LaMarr Baucom
Wireless Network Engineer
Murray State University
(270) 809-2299
lamarr.baucom@murraystate.edu

MSU Information Systems staff will never ask for your password or other confidential information via email. 


If reproducible you should attempt to catch this in a packet capture.
Load balancing should never "kick off" a user, it only takes affect upon initial association to the AP. load-balancing does nothing to 'already associated' clients. 
The "ap busy" message (code 17) is not always honored by the client.


Have you modified any of the default thresholds?

-----The EDUCAUSE Wireless Issues Constituent Group Listserv <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> wrote: -----

To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
From: LaMarr Baucom <gbaucom@MURRAYSTATE.EDU>
Sent by: The EDUCAUSE Wireless Issues Constituent Group Listserv <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: 10/23/2013 08:49AM
Subject: Re: [WIRELESS-LAN] Cisco "Client Load Balancing"

I had similar issues in our Residence Halls on 7.4, but Cisco and support forums advised me against using Client Load Balancing and Client Band Select.  I made two changes and I haven't had a report of this since.  First, I reduced the amount of APs I had in the Vlans.  The second thing was enabling bandwidth constraints on the SSIDs.  What model APs are you using?  How many APs per Vlan?  Are you using any QoS? Before upgrading our APs we also had these issues, but since upgrading them to the 1600/2600/3600 series the fixes I mentioned worked.

LaMarr Baucom
Wireless Network Engineer
Murray State University
(270) 809-2299
lamarr.baucom@murraystate.edu

MSU Information Systems staff will never ask for your password or other confidential information via email. 


This recommendation is specific to Cisco Wireless IP Phones but if Aggressive load balancing can cause a problem with an IP Phone it likely could cause the exact same problem with Skype. "• Aggressive load balancing must be disabled for each controller. Otherwise, the initial roam attempt by the phone may fail, causing a disruption in the audio path." http://www.cisco.com/en/US/docs/wireless/controller/7.5/config_guide/b_c... Your students devices running Skype might be switching between APs at the time they notice the problem. We had a similar problem with FlexConnect APs and the DHCP required option, the problem was only triggered when devices roamed from one AP to another but that turned out to be often enough to cause significant problems for our students.
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