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Community Member

Configuring Option 43 for a Cisco 4400 Wireless Controller


I have a Cisco Wireless Controller Model 4402 with 1131 Model APs. I am trying to get the APs to see the controller, but no success. I am using a Lucent QIP DHCP server (which I know very little about) and am thinking that I need to configure Option 43. Does anybody know how to do this? I have seen the options for a Windows 2003 server, but it looks completely different to configuring QIP and I can't find anything to help on the internet, (searches bring up PXE stuff). The APs get their ip address from the DHCP server, (whether they are on the same or different subnet), but their details don't appear in the Controller config. Any help is appreciated.

Cisco Employee

Re: Configuring Option 43 for a Cisco 4400 Wireless Controller

Hi Friend,

The best and easy way will be to put the AP is the VLAN which is same as that of management VLAN on the controller so that AP can learn the management IP of the controller by all subnet broadcast.

Once AP learns the IP address of the controller via Discovery process it will join the controller and once join the controller you can take the Ap and put it in any VLAN which you want because AP would have already learnt the IP Address of the controller and it will be in its NVRAM it will again join the controller and after that any AP who comes up in any vlan can join this controller via OTAP which your first AP will advertise the controller management IP address over the air.



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Community Member

Re: Configuring Option 43 for a Cisco 4400 Wireless Controller


Thanks very much, that worked perfectly. I initially had an issue with it, whereby to connect the AP, I allocated a switch port of the router, (an Enterasys SSR8600 with an 8-port switch fabric module), to the same VLAN that the Controller was on and the port kept flapping up and down.

I then set the duplex to half on the switch port, but no joy. I then connected a basic hub between the AP and the swich port on the router and the AP could then see the Controller.

Any ideas on what could have caused the flapping? It does't matter now that its up, but I'm at a loss to think why it could affect the router that way, if it wasn't the duplex setting.

Thanks for the help though,



Cisco Employee

Re: Configuring Option 43 for a Cisco 4400 Wireless Controller

Hi Gerry,

Good to know that your issue is resolved. The reason AP port could be flapping can be because of negotiation problem between Entrasys port and Cisco AP ethernet port.

I am not sure of the specification of Entrasys switch but I believe it is because of ngotiation problem. Instaead of putting the duplex as half can you hard code the duplex to 100 and speed to 100 on your Entrasys switch and see if that resolves the issue.

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