We have had a large amount of issues with timing since converting to the light weight solution, so this would not surprise me if it is another timing issue. However, we have focused on the 802.1x issue with dhcp primarily because the vista wireless devices do not appear to operate in the same manner as the vista desktop computers running 802.1x. It was my impression that the laptop would ask for a new IP address after user authentication, as well as after machine authentication. This is what happens on a desktop running 802.1x, but when the laptop goes through the user authentication phase, it does not request a new dhcp address. One Microsoft technote lead us to believe the time-outs on Vista were different than Xp and that is why the XPs work and the Vistas do not. The XP machines do request new ip addresses after user authentication on wireless, as on wired.
________________________________ From: The EDUCAUSE Wireless Issues Constituent Group Listserv on behalf of Jorge Bodden Sent: Tue 7/22/2008 8:31 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Vista Issues Seeing Wireless Network Chip, The thing is that I do not even see the networks in order to establish/attempt physical connectivity. For your problem, it seems like it is a DHCP lease time issue. If the device maintains connectivity (which from what you are telling me it does), it will not try to renew it's IP address until half the time of the lease time. Most vendor cards are not aware that they are on a new VLAN (i e they do not look at the VLAN tag on the frame). What I think is kind of funny though is that you are telling me/us that it only happens to Vista devices. I am actually surprised that it works with other devices. I think none of them should work, unless somewhere along the line you guys kill the connection between the devices and the network. I would still try to change the lease time on that guest subnet to a much lower time and force the machine to want to ask for a new IP address much sooner than 20 minutes. Thanks for the response. Greene, Chip wrote: > Might not be related to your issue, but could be a different angle, or way to > look at the problem. > > The problems we are experiencing are the way the Vista machines are handling > the 802.1x dynamic vlan assignments and dhcp requests. When the laptop > completes its machine authentication, it is placed in the guest/controlled > vlan and receives an ip address from that dhcp range. When the user > authenticates, the vlan assignment changes, but the Vista laptop does not > request a new ip address from the new vlan. After a 15 - 20 minute wait, the > laptop tries to renew its dhcp assigned address, we send a NAK for the > current address and assign the correct address. If we force Vista to repair > its connection, it will request a new ip address and work at that time as > well. > > We believe the issue is caused by the Vista laptop not requesting the > address, and not the Cisco conrtollers not passing the request, but are still > troubleshooting. All other OS and devices dor not experience this issue, that > we are aware of. Our network is Cisco LWAPP with 1130 and 1242 aps. All > SSIDs are broadcasted and seen by all devices. > > Chip Greene > Senior Network Specialist > University of Richmond > > > ________________________________ > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv on behalf of > Jorge Bodden > Sent: Mon 7/21/2008 11:28 AM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: [WIRELESS-LAN] Vista Issues Seeing Wireless Network > > > Hello All, > > I was wondering if any of you guys have experienced this type of behavior. > > I had a device that had no connectivity issues at the first location. Then > when I moved it to another/second location it was not able to see any of > these networks, at all. I thought that it may be a difference in the way the > two controllers were set up. Therefore, I put all the APs at the second > location on the same controller as the APs in the first location. This got > the same results. > > I have read several articles pertaining to issues with Vista and SSIDs that > are not broadcasting. But all my SSIDs are broadcasting. However, we are in > the middle of testing to see if the laptop now works at the site when telling > the PC to connect to a network that is no broadcasting. But if any members > of the group have seen this issue before, and could provide information, it > would be greatly appreciated. > > Thanks > > Jorge Bodden > > btw...all other devices work fine (XP, Macs & Linux) > > -------------------- > > This electronic message is intended to be for the use only of the named > recipient, and may contain information that is confidential or privileged. > If you are not the intended recipient, you are hereby notified that any > disclosure, copying, distribution or use of the contents of this message is > strictly prohibited. If you have received this message in error or are not > the named recipient, please notify us immediately by contacting the sender at > the electronic mail address noted above, and delete and destroy all copies of > this message. 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