Wifi clients does not the IP from new Windows DHCP server

[LBon27622]

Hi. Moving a Windows DHCP server - our WLC 2500  8.1.102.0 uses this for assigning IP addresses. The two are on different subnets and there is a IP helper on the switch pointing to the Windows DHCP server. If I change this IP helper to point to the new DHCP server (containing the same settings as the original; backup/restore), does not result in wireless clients getting IP adresses from this server - what am I missing?

The advanced tab for the VLAN for WiFi clients shows DHCP Override and DHCP Addr. Assignent Required sttings. What are those - can this (or some other setting on the WLC) block IP requests to the new server?

Regards, Lars.

[Sandeep Choudhary]

dd you Point either your DHCP override to the new DHCP server IP address Or, you can use the DHCP option of the controller interface configuration for the interface.

check the posts:

https://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/110865-dhcp-wlc.html

Regards

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[LBon27622]

Neither DHCP Override nor DHCP Addr. Assignent Required are checked. But the cisco network switch has an IP helper pointing to the old (and working) DHCP server. If I change the IP helper to the new server, wifi clients no longer gets an IP address

Regarding your link - want I prefer (and what I expect is configured) is the transparent setup so that clients requests IPs directly to the Internet Windows DHCP server.

Regards, Lars.

[Scott Fella]

Connect a laptop that is wired to the switch the controller is connected to and see if it pulls a dhcp address. Make sure you test each subnet to make sure, it can be that the vlan is not spanning across your Infrastructure.

[Sandeep Choudhary]

Did you enter new DHCP server IP under dynamic interface ?

see my posts about external DHCP server:

https://rscciew.wordpress.com/2014/07/16/dhcp-with-the-wlc/

Regards

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[johnd2310]

Hi,

What DHCP server is set on the Interface of the wlan? You will find interface on Controller-->Interface tab

Thanks

John

[LBon27622]

Ah - here the DHCP points to our cisco switch - on which we have configured IP helper. Could the IP helper from the switch be cached or similar? Maybe I should just point to the new Windows DHCP directly in the interface tab?

Regards, Lars.

[LBon27622]

...and DHCP Proxy Mode is set to "disabled"

Regards, Lars.

[Scott Fella]

Have you verified that dhcp works by connecting a wired laptop on the vlan that the wireless clients would be connecting to? Verify that first as I would suspect that is not working. Then takes steps to trace where the issue is, either with wrong ip helper on the L3, vlan not spanning then with the controller.