This is a known bug with server version 4.1.3 - I'm not sure if it happens in previous versions. What I understand is happening is that it's a problem with the server but that the client doesn't understand what the status on the server of a given IP address is. From what I've heard, it's a code fix required on the server level (not the client). Go figure.
I think the client treats the workstation with the IP address as if it was the workstation that previously had the IP address - so client behavior relating to the role of the previous IP address holder is transferred to the current IP address holder. In our experience, network access does not follow (phew!) It is seriously exacerbated in our environment because IBM access connections on our 50% Lenovo campus cheerfully sends a DHCP release packet when it closes a wireless connection, so our IP addresses on the wireless vlan are changing many times a day as users move around. We're piloting IP address reservations (yuk!) to see if this alleviates the symptoms.... ________________________________ From: Cisco Clean Access Users and Administrators [mailto:[EMAIL PROTECTED] On Behalf Of Aaron Abitia Sent: Thursday, March 20, 2008 10:10 AM To: [email protected] Subject: Re: "OS Mismatch Detected" suddenly appearing on 4.1.2.1 Bruce, Thanks very much for that tip. This is the exact sort of behavior that we're seeing, only on a larger scale. I worked with a user who had this problem, and sure enough, the IP address they got from our DHCP server was already added into CCA for a different username; once I kicked that old username--since that user had apparently already packed up and left--my problem user worked immediately and the OS mismatch went away. So, the root of the problem seems to be that CCA apparently isn't terminating sessions after the user is gone, but our DHCP server HAS terminated the session and has taken the IP Address and now given it to someone else. The question now is, why isn't CCA ending the session, how does CCA know to end a session, and is that timer configurable. Any comments from you (or anyone) is hugely appreciate. Thanks, I think we're very close to fixing this problem completely. -Aaron On Tue, Mar 18, 2008 at 2:52 AM, Osborne, Bruce W. (NS) <[EMAIL PROTECTED]> wrote: Aaron, In the past on 4.1.1 I have seen this when Clean Access thinks somebody else with a different OS owns that IP (usually XP vs. Vista). Search Online Users or Certified Devices for that IP and kick the other users. Bruce Osborne Liberty University From: Cisco Clean Access Users and Administrators [mailto:[EMAIL PROTECTED] On Behalf Of Aaron Abitia Sent: Monday, March 17, 2008 7:59 PM To: [email protected] Subject: Re: [CLEANACCESS] "OS Mismatch Detected" suddenly appearing on 4.1.2.1 Users can successfully get a DHCP address and all looks normal there, and the certified list for the successfully logged-in users looks to be fine. But for the ones who cannot get the pop-up for logging in, that's where they are stopped: the Agent will not pop-up to allow login. Nothing seems to make it want to pop-up, and then you see the "OS mismatch detected" in system tray. The next day, all will work correctly. It appears to be happening over 6 CAS boxes in our wireless network, but not to everyone...sometimes it will work, other times it will not. Theoretically, I can see that perhaps the 8905 udp communication could get blocked or interrupted in some way, thus not allowing the pop-up to happen, but why then the message "OS Mismatch Detected"? You'd think the machine would just sit there, with no Agent pop-up, and no error message. Thanks. -Aaron On Mon, Mar 17, 2008 at 4:10 PM, Branden Kirk <[EMAIL PROTECTED]> wrote: Do users appear correctly in DHCP and in your Certified users list? I had that error on a single user and nothing on the scale you're speaking of but I noticed a mismatch in those areas. Branden On 3/17/08 3:37 PM, "Aaron Abitia" <[EMAIL PROTECTED]> wrote: We have had a strange problem come up...we just started getting the message "OS mismatch detected" on windows XP wireless laptops on CCA. We are running 4.1.2.1 <http://4.1.2.1> <http://4.1.2.1> successfully for the past couple months; we have two managers in redundant mode, and 6 CAS boxes. On my test machine, I can connect to the wireless network and get an IP address fine, but the Agent does not popup and when I put my pointer over the CCA agent icon in the system tray, I see the "OS Mismatch Detected" error. This same laptop has had no changes of any kind, has worked fine since we turned CCA on, and there have not been any CCA changes of any kind. I stopped and restarted the Agent, but it didn't help. I completely uninstalled and reinstalled the Agent, but that didn't work either. When I take that laptop to another area of campus, fed by the same CAS box (only a different vlan), it works fine. If I take my laptop back to the trouble area, it will suddenly work fine; a day later, if I go back there, it will stop working and show me the OS mismatch error, so it all appears to be intermittent, with seemingly no pattern. I would estimate that 25% of our users in our Library are unable to use wireless due to this problem. We are not doing any posture assessment/repair on our CCA network; it is log in via Agent only, at this time. I have a case open with Cisco, but thought I'd see if anyone has seen this before. Many thanks! -- Aaron Abitia Network Analyst Network Administration, ITS Cal Poly State University Tel: 805.756.1295 -- Aaron Abitia Network Analyst Network Administration, ITS Cal Poly State University Tel: 805.756.1295
