AP541N DHCP Issue - Firmware Version AP541N-K9-2.0(4)

[jemery482]

Enovironment

     7) AP541N-K9-2.0(4) Clustered

     2) SSID's on VLAN1

     WPA/WPA2/TKIP/CCMP

I am finding that wireless clients (Phones, Laptops, IPads, Tablets, Etc) won't connect and get an IP address.  They do authenticate with the wireless but never obtain an IP address.  I have researched these AP's and DHCP issues and this appears to be a common problem.  Which was suppose to be fixed in the newest firmware release.  I have tried the registry tweaks that are mentioned for the DHCP server, that didn't work.  I've tried other attempts at fixing this and nothing has made a difference.  The only thing that fixes it, is to reboot the trouble access point.  Then clients connect fine for a couple hours to a couple of days then they need another reboot.

Here is an example of what is in the log:

hostapd: wlan0: IEEE 802.11 STA 24:ab:81:ab:86:6b deauthed from BSSID 00:21:29:00:dd:50 reason 3

hostapd: wlan0: IEEE 802.11 Assoc request from 24:ab:81:ab:86:6b BSSID 00:21:29:00:dd:50 SSID wwtcwifi
hostapd: wlan0: IEEE 802.11 STA 24:ab:81:ab:86:6b associated with BSSID 00:21:29:00:dd:50
hostapd: wlan0: STA 24:ab:81:ab:86:6b WPA: pairwise key exchange completed (WPAv2)
hostapd: The wireless client with MAC address 24:ab:81:ab:86:6b has been successfully authenticated.
hostapd: wlan0: IEEE 802.11 STA 24:ab:81:ab:86:6b disassociated from BSSID 00:21:29:00:dd:50 reason 8

Let me know ASAP if there is anything that can be done.

[Tom Watts]

Hi Jemery, the one thing that is unfortunate is you have a cluster of 7. If one of the AP's has a problem it may reciprocate across all of them.

Is it at all possible to test by removing 1 AP from the cluster and see how the other 6 do vs the 1 isolated one?

Other things may be recommended such as setting the ethernet port to a non auto negotiation on the switch it is connecting to.

-Tom
Please mark answered for helpful posts

[jemery482]

Tom,

I have removed the AP from the cluster.  Here is what I have done in my troubleshooting.  Note this AP already has been swapped out once and the problem still existed.  It seems to happen about every ten days.

6/1/13 - Couldn't obtain DHCP from the unclustered Access Point.

Laptop was connected to wireless but unable to obtain IP Address

                Test with my Phone - Confirmed it was not working

                Set the Switch Port to 100 Full on 100 Meg Switch for the POE Injector - Still Not working

                Moved the Injector to the Gigabit Switch - Still Not working

                Plugged the AC Adapter into the access point while it was Powered over Ethernet - Still Not working

                Moved LAN Cable to switch instead of through injector - Still Not working

                Removed my Phone MAC from the MAC Filtering List and added it back in - Still Not working

                Removed MAC Filtering from AP - My Phone still not working

                Turned off Rouge AP Detection - Still not working

                Tried different Wireless SSID - Still not working

                Configured Wireless Network VAPS to Disabled for MAC Filtering - Still Not working

                Turned off Wireless Radio in AP and Turned back on - Started working *AP PROBLEM*

Factory defaulted the AP

Reloaded the Firmware Image

Factory defaulted the AP again

Setup the AP like the rest without MAC Filtering

6/11/13 - Couldn't obtain DHCP from the unclustered Access Point.

Fired up another DHCP problem to see if it was a Windows DHCP Server compatibility issue - didnt work

Same exact problem on 6/1/13.

Turned Wireless Radio Off then back on and all was good.

Replaced POE Injector today to see if that makes a difference.  - working now but wont know for another ten days.

I have had multiple troubles with these AP541's inside our business and at other businesses.  Seems like after ten days the Wireless Radio has to be turned off and back on to fix the DHCP issue.

Let me know your thoughts.

Jeff

[Tom Watts]

Jemerey, this is a pretty good posting with some very good steps.  Not much to say. Seems like the VAP is hanging or something like that. Couldn't imagine why.

-Tom
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[jemery482]

I am still having the same issue, is it possible to engage a cisco engineer at this point.  I replaced the access point with a brand new one also.  I have done countless hours of troubleshooting to fix the DHCP issue on the AP541 Access Points.

[anelsen84]

Hello, I am having this same exact issue. These DHCP issues are  definately still a problem in the 2.0.4 firmware. Very disappointing.  Please let us know if there is a beta firmware or a workaround for this  problem ASAP. Thanks!

[ernesto_rico]

I have the same problem, and my environment is kind of similar to Jeremy, i have 15 AP's in a cluster and i must reboot all the AP's at least  once a week in order to don't get issues....

[fernando.gamero]

I have this same issue- need to reboot the AP once or twice a week. I'm using a clean channel (11 on 2.4 ghz) and its not congested at all. No firmware has been release for a while, I hope CIsco can address this issue soon!