Re: WAP4410N does not renew DHCP lease

philipmcnaull · ‎06-24-2010

I have several Cisco WAP4410N access points. They are configured to automatically obtain an IP address through DHCP. This works fine, but I've discovered when the DHCP lease expires, the access point doesn't renew it. It continues to use the same IP address but does not renew the lease. If I reboot the access point, it will renew the lease again.

Is this a known issue with the WAP4410N? Is there any way to work around this, other than setting a static IP address or rebooting regularly?

Min Thein Oo · ‎06-28-2010

I also have same issue like this incident. I have several access points but DHCP is hosted on Catalyst 3560 PoE Switch. AP power is provided by PoE switch. A few days later, Windows Vista notebook can not get DHCP Address wherease Windows XP has no issue. After rebooting the AP, all notebooks are assigned by DHCP. Currently all APs are needed to reboot regular. All APs is updated to firmware version 2.0.1.0. Any suggestion from Cisco? Thanks

ernestoabarca · ‎11-27-2015

Hi,

I know this topic is rather old, but in case i helps somebody in the future... my DHCP lease time is 1h and still it happens.

I think I found the problem, seems there is a bug in the way ACL works (Through seems to work fine on most situations).

But wait, first of all, and maybe the reason to appear this problem 'randomly': WHY I should set "Wireless Connection Control" to LOCAL to be allowed to see the wireless clients connected????? That option should be always available!

The apparent reason for DHCP not working is:

- When you activate "wireless connection control", I.E.: see who is connected.

- AND even if you check "PREVENT following MAC addresses from connecting to wireless network"

- AND you leave the MAC list empty

- AND after some.. hours?

It stops relaying DHCP requests

I have latest firmware version: 2.0.7.8

Easy solution: disable at all Wireless connection control if you don't need it.

If you connect by SSH you can see the configuracion is correct so maybe the concept of MAC table "TRUSTED stations list" is not working perfectly.

Is somebody able to verify it too?

Csaba Vasarhelyi · ‎07-13-2010

Hello there,

I have the same problem that Phillip has. APs are using the latest firmware, but because of WPA2-Personal Mixed security mode, computers can't renew their IP address through the DHCP request because the AP doen't forward the DHCP requests. Furthermore, static IP works well but we have many clients so it won't work. Wired clients can renew their ip address through DHCP.

bizcraft01 · ‎10-13-2010

I am also having the same problem.

I have a PID/VID of WAP4410N-A V02 with firmware 2.0.3.3.

On boot, it obtains its LAN IP address via DHCP from a Linksys RVS4000 v1 with firmware 1.3.2.0. The lease time is 1 day (86400 seconds).

After the lease expires, the 4410 fails to renew the lease. No other functions of the 4410 appear to be affected. Its internal web server remains responsive, and WLAN clients with unexpired DHCP leases also issued by the RVS4000 remain online.

However, as each WLAN client's existing DHCP lease expires, the RVS4000's DHCP server's active IP table shows a renewal lease for only 60 seconds, and a garbled hostname. The 4410 does show that the WLAN clients remain authenticated--their MAC addresses remain in its Wireless Client List. Each WLAN client in this state reports "No Gateway" errors when connecting to the WLAN and the RVS4000's DHCP server assigns only a 60 second lease, even though the same IP address is reassigned to each WLAN client. it appears that the DHCP reply never makes it to the WLAN client, and that the DHCP requests are garbled in some way.

No LAN hosts are impacted by this behavior. They continue to renew their DHCP IP leases and receive normal 1 day leases.

When I reboot the 4410, it naturally requests an initial IP address from the 4000 and all is well until that lease expires, and then the problem repeats.

It is annoying to have to reboot the 4410 every day.

I am at the end of my wits for a solution to this problem.

Can anyone point me toward a fix?

philipmcnaull · ‎10-18-2010

I did discover later that if the DHCP server's lease time is set to two hours or less, then the WAP4410N will renew its lease correctly. But if the lease time is longer, it doesn't work. You might try shortening the lease time on your DHCP server if it is practical for you to do that.

ali_alzand · ‎10-18-2010

I have four of them in my network and Have the same Issue, rebooting solve the issue for a period of time and then it will come back again. I wish there is a permanent solustion for this Issue

Min Thein Oo · ‎10-18-2010

I have 28 WAP4410N access points and it becomes routine job to reboot all APs every morning just before office hours since June 2010 because of having same issue. During office hours I frequently check syslog server, where all APs dump their syslog, if I find clients trying to associate a particular AP with many times, I reboot this AP again instead of waiting user’s complaint.

It is really strange that if a client cannot connect to a particular AP, it may connect other neighboring APs by moving the notebook closer to them. The existing connections on that particular AP have no issue, here, usually not more than 8 concurrent connections and under 15% cpu utilization of AP.

In my case, because clients can connect/associate other APs, and so it couldn’t be DHCP service issue. At the DHCP side, IP is already issued to related MAC address and it renews lease time as well. But only client don’t receive IP address, and get “limited connection access”. I hope Cisco will find a permanent solution quickly.

David Carr · ‎10-26-2010

Hey guys, have any of you tried what Philip posted about shortening the lease timers? If so, post your test results if you don't mind. If the lease timers don't work, call into the SBSC and get a documented case so we can try and fix this issue. Thanks.

Min Thein Oo · ‎10-27-2010

Hello, I have logged the case to Cisco since 29/June/2010. I believe Developer team is aware my case and they are still working on it. Please let me know if you want my case ID. Thanks

bizcraft01 · ‎11-30-2010

I have been using Philip's suggestion re. shortening the DHCP lease time to 2 hours. After several weeks, no problems at all. It's been great to not have to reboot things every day or two. Thanks for the idea.

I still strongly prefer that Cisco fix the root cause under warranty, as some OS's TCP/IP stacks have been known to reset all active connections when the leases get renewed, and the lease TTL on my Cisco RVS4000 is a global setting that cannot be applied to a specific MAC. I have ADSL Lite, but it can still take several hours to download DVD images, during which time the lease must be renewed at least once.