DHCP_REQ Bug??

Unanswered Question
Jan 9th, 2009

I have a strange reoccurring problem. First some background on how we are setup. I have 6 4404 WLCs each licensed for 100 APs. They are all running version 5.0.148.0 configured the same using WCS version 5.1.64.0. Each have 7 WLANs defined. One of the WLANs is an open guest WLAN. We are NOT using anchor controllers for guest traffic; it simply is defined to a guest VLAN interface that routes through a virtual interface on our ASA5520. We do allow DHCP traffic through the ASA to our enterprise DHCP server. The guest WLAN is configured to require DHCP address assignment. All works fine for the most part and has been for over a year. The problem is that about every 30 days or so we will have a report of some guests not able to get an IP address. I will look at WCS and find that on one controller everyone connected to guest has an IP address of 0.0.0.0 and their Policy Manager State is at DHCP_REQ. If I reboot that controller all is fine for another 30 days or so. This only happens on two of my six controllers. By the way, I need to run version 5 due to an application that requires the ability to use WorkGroup Bridges. Thanks for taking the time to think about this!!!

Doug

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
gjcluttrell Sat, 01/10/2009 - 07:01

A few questions first:

Is your enterprise DHCP server a Microsoft Windows DHCP server?

Is the DHCP server giving leases withing a LAN or across the WAN?

Is it the same WLC doing this all the time or is it different ones every 30 days or so?

rajesh_san Thu, 05/21/2009 - 03:40

HI Doug, I'm facing with the same issue every 30 days. did you manage to solve the issue? It would be helpful if you could share me with some hints to solve this...

THanks!

dbuttry Thu, 05/21/2009 - 05:00

The short answer is no, I did not solve my problem. I assumed this was a 5.0.148.0 bug so I upgraded my controllers to 5.2.157.0. This caused me worse problems (search the forums for dbuttry) so I downgraded everything to 4.2.176.0. After lots of work to get things stable again, I still have this issue with one of my 6 controllers, now running 4.2.176.0. If you figure this out, please share!! Thanks.

brian-p Thu, 05/21/2009 - 10:34

We had very similar problems. There is a bug (CSCsq23961)with the controller code 4.2(112) - 5.1(151). It is fixed in 5.2. We spent monthes trying to diagnose random wireless problems before we realized it was DHCP related. Basically the controller randomly drops the DHCP replies from the server to the client. The bug details list a work around by creating a dummy DHCP pool (not even related to any of your existing networks) on the controller. This seems to work also. Hope this helps.

Brian

Actions

This Discussion

 

 

Trending Topics: Other Wireless Mobility

client could not be authenticated
Network Analysis Module (NAM) Products
Cisco 6500 nam
reason 440 driver failure
Cisco password cracker
Cisco Wireless mode