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WLAN DHCP Timeout

I am troubleshooting a dual 4404-100 WLAN controller implementation. The two controllers have all 4 ports connected to two 6509 core switches using 4 ap-manager interfaces. I have checked every step between the controller and the DHCP servers I can think of, including:

1. DHCP server address on the WLAN VLANs

2. ip-helper address on L3 interfaces on the switches

3. DHCP server address on the ap-manager interfaces

4. APs are using spanning-tree portfast

5. DHCP server is reachable from the controller and access ports

I am getting feedback from users that DHCP works inconsistently, and sometimes on 2 of 3 WLANs but not the third. I honestly cannot think of any configuration issues. I was considering turning off DHCP relay and allowing the DHCP requests to be bridged to the wired network as I have ip-helper address configured on the L3 interfaces that the APs are on.

Any thoughts?

Thanks,

Scott

1 REPLY

Re: WLAN DHCP Timeout

One thing to take a look at is the debug client on both of the 4404 at the same time. Sometimes you'll see what looks like the client trying to associate to both controllers, this can happen if there are AP from both controllers that the client can hear. You should see some message similar to this " dropping DHCP request due to mobility". If this is happening you may need to take a look at AP placement.

HTH

Steve

HTH, Steve ------------------------------------------------------------------------------------------------ Please remember to rate useful posts, and mark questions as answered
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