Problem solved, and self inflicted.
We have over 120 dynamic interfaces on our 28 controllers, and as you know by design they need to be in the same VLANs as user IP addresses (unless you have infinite IP space). We register these in our system so they are protected from being given out as client DHCP addresses, but I've found that a few of these somehow backslid into our DHCP pool and were being assigned to clients, hence creating an IP conflict where a client and a controller dynamic interface had the same IP address. These IP addressed dynamic interfaces are paramount to system function, but they can't be reliably monitored (often don't respond to ping, by Cisco literature) and alerting on duplicate IPs is just not there in a meaningful way. Hopefully this improves at some point. Sigh. Lee H. Badman Wireless/Network Engineer Information and Technology Services (ITS) Syracuse University [email protected] 315.443.3003 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Lee H Badman Sent: Sunday, August 30, 2009 6:38 PM To: [email protected] Subject: [WIRELESS-LAN] 5.2.193 Cisco Controllers- "Freeze Ups"? Wondering if we're alone in this experience. We had a great opening weekend in that thousands of users got on our secure wireless network with little fanfare. Then tonight, multiple controllers seemed to have simple "frozen" for lack of a better description- all indicators were fine except dhcp renewals and new requests were not getting back to the clients, and established users' traffic stalled. The fix seemed to be moving APs to another controller, booting the one with the stall condition, and moving the APs back. Simply rebooting APs didn't seem to touch it. Anyone experience similar? We've never seen anything like this on past versions. I'm not pointing fingers at the code at this point, but would be curious if anyone else has seen the same sort of problem. Lee H. Badman Wireless/Network Engineer Information Technology and Services Syracuse University 315 443-3003 ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
