Wireless client cannot get IP address

[springman]

I set up the AP1231G a few months ago. All of a sudden, client computer cannot get IP address any more while it can still see and connect to the AP. It looks like something wrong with DHCP but I did not change any setting at all. Before I make a TAC call, I hope I can get a solution from this NetPro group. Thanks in advance.

[dwillie]

Hi Springman,

I am seeing a similar problem with my clients as well. I'm running (2) 4402 WLC, with wireless laptop's, intermec scanners, and 7921's as client side devices. Originally, we were set up with our centralized DHCP server, and all client devices would magically lose their IP address. We then reverted to using the WLC DHCP Internal Server which fixed the 7921's and the laptops; however, the scanners continue to get an IP address, then magically lose it at various times during the day. When this occurs, the default IP address shows up 169.XX.XX.XX on the client device, requiring the user to cold boot the device to renew the IP. Really strange DHCP operations on the WLC. Does anyone have any ideas?

[jeffreydrago]

Hi Springman/Dswilleus

Same problem here running intermec scanners.. Any clues?

[john.preves]

can you make sure you still have addresses left in your DHCP scope? I would check things like lease times, subnet masks to make sure they are correct and then I would statically assign all of your AP's with an address so this doesn't happen again.

[john.preves]

my bad I just re-read the clients having issues... it's late, but the first two suggestions still stand.

[dennischolmes]

One of the common problems causing this symptom is that the client although associated is not active. Try extending your User Idle Timeout setting for the controllers to a period longer than 300 seconds. I actually set it for an entire 10 hours when the client device is a RF Gun or manufacturing device. This covers an entire shift. What happens is the device might not be used for a 5 minute window which causes the WLC to break the session. The device doesn't know the session is broken because it went into power conserve mode (sleep) but did this while still associated. When the client wakes up it is associated to the AP but has lost its authentication approval and address. It reconfigures for the default failed IP address. Just a thought to try.

[Scott Fella]

With handheld scanners, you have to set the power setting to CAM.... it's the only way it will work but you will sacrifice battery. Idle timeoute will help like Dennis mentioned, but if you are using 4.2.61 on the WLC.... 9999 seconds is the highest value you can set without having more issues until they come out with a fix on a newer version.

[dennischolmes]

If you set to the number zero (0) then I believe that sets the setting to infinity. I may be mistaken, but I believe that is correct.

[jeffreydrago]

I'm using CAM mode and not using WLC... I have 13 1231 Aps in Autonomous mode... Is there a Idle Timeout on autonomous?

Thanks.

[Scott Fella]

Well since you are already using CAM and the ap's are autonomous, then no.... there is no idle timeout setting. Are you haveing this issue with all of the scanners or some? Also are you having this issue on all ap's. If you are on both the above, can you replicate the issue. I had a client that had the same issue and it was a procedure they users were told to do that would hang the wifi connection until the unit was rebooted. You should also talk to the manufacture fo the scanner to see if they have seen this issue and if there is a fix.... or newer firmware.

[jeffreydrago]

Hi Fella, tks so far.

I'm having in all scanners and this includes a mix of Samsumg, Intel and Winstron Radios. I already upgraded all the firmwares and talked to the manufacturer. I'm just hoping that it is a dhcp issue.