Wireless WLC vs WCS Internal DHCP Server

[anthonykahwati]

Hello

I am trying to set up an internal DHCP scope per WLAN on our WLC. It does not like to allow me to do so, it complains that there was an error in setting the dhcp override configuration. The thing is, I am setting this up in the same way as I have done in the past on a WCS.

What I am doing is creating a Dynamic Interface, creating a DHCP scope in the range of the Interface, then, in the advanced configuration of the WLAN itself, trying to get the DHCP overide to point to the IP address of the WLC itself. It does not like it and throws an error.

Essentially, my aim is to create multiple WLANs, each with its own IP range which is handed to the clients by the WLC.

Can anyone thing of a reason for this not to work? We are using WLC 7.4.110.0 on a 5508.

I have done this on a WCS under the controller section and it works fine, so, essentially, this is the same thing but without the WCS configuring the controller.

Thanks in advance.                  

[johnmedcraft]

Under the interface did you point the ip address of your primary DHCP server to the management ip of the WLC?

[anthonykahwati]

Thanks for the reply John. I have just tried that. The Interface took the management IP of the WLC as the Primary DHCP server, however, when I then try to set the DHCP server of that WLAN to the IP address of the Interface, it gives me the same error.

What you say sounds like a correct way of doing it, but no joy...... Do you know if you can set the DHCP server in a WLAN on a WLC to be the Interface of the WLC on that scope?

[johnmedcraft]

Hi -

Are you able to provide screenshot of the interface in question and the DHCP scope you are configuring?

[anthonykahwati]

A brief outline of my config:

WLAN: our Guest

Dynamic Interface: ourGuest

ip 172.25.0.240

mask: 255.255.255.0

gateway: 172.25.0.254

primary dhcp server (was blank, but now 192.168.40.1)

DHCP proxy enabled

DHCP Scope: 172.25.0.1 - 239

network: 172.25.0.0

netmask: 255.255.255.0

default gateway 1: 172.25.0.254

enabled: yes

When I try to set WLAN / ourGuest / advanced / ..... to

DHCP Server - Override: Yes

IP 172.25.0.240

DHCP Addr. Assignment Required: Yes

I get the error. Any other IP address in that range, whether in the scope (1 - 239) or out of it (240 - 254) will be accepted, it just wont accept the address of the interface..... unfortuantely, this leaves me stumped on how to create a scope on a per WLAN basis.

I hope this is useful information.

Thanks

Anthony

[johnmedcraft]

What it the error you recieve.  Also you should be able to create a basic scope without any of the advanced options changed.  if you remove the advanced options do you recieve the error?

[anthonykahwati]

[anthonykahwati]

I do not receive the error, however, there is then no way of the WLC knowing which scope should be used for that WLAN is there?

[anthonykahwati]

Sorry, I did not answer your question on the error.... Once I enter the details, I am warned that users may get disconencted for a moment then the following:

[johnmedcraft · Accepted solution]

Because you have created the 172.25.0.x DHCP scope on the WLC and under the interface you applied the DHCP server to the management IP of the WLC with the network 172.25.0.x this is where it will get the infomation from without having the boxes checked.  You would of then assigned the interface to the wlan for you to connect to.  as long as both the scope and WLAN are enabled this should pick up an address.  I have been caught out may times before putting the the wrong IP address for the primary DHCP server.

[johnmedcraft · Accepted solution]

Now you have unchecked the DHCP override, to test if you set the WLAN to open authenication under security do you get an IP address now you have also pointed your DHCP server to the WLC?

[anthonykahwati]

Hi John.
Thanks very much. You are spot on.
Much appreciated!
Anthony

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