End clients receiving wrong DHCP subnet leases

[nathant]

Hi Team,

I have been experiencing a DHCP lease problem where a number of users who connect to an SSID receive an invalid subnet lease (or wrong DHCP allocation), whilst other users can connect to the same SSID and receive a valid IP address assignment.

All of my APs are in FlexConnect mode and the problem is not AP specific (this occurs across all the APs).

The Cisco Wireless LAN Controller (WLC) and all the APs are on software version is 8.3.143.0

The WLC is configured with a static IP address of 0.0.0.0 to discover and find the external Windows DHCP server.

Any help would be greatly appreciated.

Regards,
Nathan.

[marce1000]

 - Check the DHCP server's logs for the particular mac-addresses from the clients getting a 'wrong ip' ; check wether the dhcp scopes are correctly configured (e.g.).

M.

[patoberli]

Are you using WPA2-Enterprise (Radius based) authentication?
If yes, maybe you have configured different VLANs in the radius server profiles.

[Kasun Bandara]

I suggest you to check, interfac mapping for each SSID and try changing DHCP server IP to specific server which release IPs.

Also, in interfaces check for the correct DHCP server and VLAN with connectivity to server from wlc.

[MatthewHickey7355]

I know that this thread is really old, so my apologies for replying on it, but this is the only thread I could find that describes my issue almost perfectly.

We're running 8.3.150.0 on a 7510 WLC. At this location they're using a variety of APs including 1142s, 1602s, and 1702s.

Clients are receiving IP addresses from the native VLAN (AP management) even though the Flexconnect group has the WLAN to VLAN mappings correct. Scopes on the DHCP server are correct as well.   Most clients on an AP receive the correct address, while simultaneously at least one client connected to the same AP and WLAN receives an IP address from the management VLAN.  This occurs randomly in terms of specific AP and time of day.  

I have a TAC case open right now on this issue, but so far no luck in determining a definitive cause.

[saad_masood_88]

Make sure that you have assigned the right interface to the Profile. 

I am using a VWLC and had exactly the same issue. Resolved by unchecking FlexConnect Local switching under the Advanced Tab of Profile. I was considering the following bug

Cisco Bug: CSCvg66604 - FlexConnect Client gets IP address incorrectly from the native vlan

Best,