Hi Sean, Glad to hear it cleared up for you...actually I kinda misspoke there and implied that we're using CCA to hand out DHCP addresses. We don't have that model here; our CCA and DHCP are separate entities, and sometimes those two entities aren't in sync with each other, leading to the OS mismatch problem. Our CCA system simply passes DHCP requests through to our Lucent QIP DHCP server. So yes, Dennis' solution is spot on for a single instance of this problem, but when the problem hit us, we had dozens if not hundreds of people with that OS mismatch error. Not pretty. Usually this problem will clear up on its own, as leases expire on the DHCP side and timeout threshholds are hit on the CCA side.
Good luck. -Aaron On Mon, Aug 25, 2008 at 3:05 PM, Hennessey, Sean <[EMAIL PROTECTED]> wrote: > Hey Aaron – > > > > That's a good point – I hadn't thought of it like that. We do not use CCA > for our DHCP but it is certainly possible that a machine may have lost its > lease to another machine in that subnet – particularly as the problem > happened on our Mac/Win repair bench. Regardless, the problem seem to have > cleared itself up for now, but thank you (and Dennis) for your help! > > > > - Sean > > > > ---- > > Sean Hennessey > > Networking and Information Security Systems Administrator > > The University of Portland > > *From:* Cisco Clean Access Users and Administrators [mailto: > [EMAIL PROTECTED] *On Behalf Of *Aaron Abitia > *Sent:* Monday, August 25, 2008 2:32 PM > *To:* [email protected] > *Subject:* Re: OS Mismatch > > > > In our case it came down to CCA not meshing correctly with our enterprise > DHCP server. If a particular DHCP subnet which is run by CCA is really > impacted, we found that CCA's db wouldn't match our DHCP db. So, as DHCP > frees up an ip address and hands it out immediately to a user, CCA hasn't > yet received word that the user is gone, so there is a conflict. If the > previous owner of that IP address was a Macintosh user, and the new owner of > that IP address is your XP user, CCA will not allow the XP user to sign on, > won't pop up the Agent and will display the OS Mismatch error because it > thinks the Mac user is still active. If the new owner is another Mac user, > the effect is that you won't see the OS Mismatch error, but the Agent will > not pop-up, again because CCA thinks that previous owner of the IP address > is still active. For some reason CCA doesn't get word quick enough that the > user logged off. We put a secondary subnet on the network in question, > which cleared up this problem. The problem happens during extremely high > usage. > > -Aaron > > > -- Aaron Abitia Network Analyst Network Administration, ITS Cal Poly State University Tel: 805.756.1295
