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I'm having an issue identifying why my Cisco vWLC with DHCP bridging is flooding my DHCP servers with REQUESTS. These requests are coming in well over 1000/min. enter image description here My Setup is in a lab, I am running a Cisco vWLC(v8.0.152) trunked to a Cisco 3560(v15.0(2)SE11) switch. The Wireless Client VLAN 107 (10.22.252.0/24) exists on both the Cisco vWLC and the Cisco 3560. There is a helper-address on the Cisco 3560 with the DHCP server defined(10.22.168.4).

What is really odd is the devices asking constantly for DHCP Request, are assigned an IP address.

DHCP Proxy has been disabled on the vWLC enter image description here

Switch SVI has a address-helper defined.

enter image description here

closed as too broad by Ron Maupin Apr 19 at 14:24

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Apr 1 '18 at 22:40
  • Still happening. This flooding is utilizing almost 100Mbs... – Jim Jun 6 '18 at 22:33
  • Those two hosts need to be checked. Unfortunately, host configurations are off-topic here. You may find an answer on Server Fault. – Ron Maupin Jun 6 '18 at 22:35
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You are seeing two mac addresses. They are most likely bouncing the packet between them. Identify the other device and check it's ip helper setup. Or your route is messed up.

  • The MAC address you are seeing is from the two clients requesting DHCP. – Jim Jun 6 '18 at 22:23
  • There are very few failures which will cause that level of utilization. DHCP will never retransmit at that rate. The only things that cause this symptom are layer 2 loops. Unplug the DHCP server, your problem will not go away. Unplug the clients, the problem will not go away. you have a loop elsewhere. – Fred Phillips Jun 8 '18 at 11:03

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