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Configure DHCP on a Aironet AP 1232AG

I am setting up an AP to be a DHCP server for Cusomters to us when they come in to our office. The problem is the AP is going to our DHCP server Windows 2003 server instead of using what I configured it to use in the AP config. Any idea as to what I am missing?

Or doesn't this AP hand out IP's to the wireless connection.

We a cheap little router that will hand out IP's

Thanks

3 REPLIES
Green

Re: Configure DHCP on a Aironet AP 1232AG

Part of the DHCP protocol (IIRC) is that the "First Server Wins"

Either the Windows server is responding quicker (likely, depending on your AP's load and the amount of noise / interference in your environment)

Or,

The AP is seeing that another server is up & active for that scope (range of addresses on that subnet) and it's deferring to it.

Either way, multiple DHC servers on the same segment with the same scopes ... can be a nightmare.

If all of your wireless NICs were Cisco (I know, visitors, you have no control), you could exclude the Cisco vendor ID from the Windows server's scope of MAC addresses to serve.

Probably the easiest thing would be to put the AP on it's own segment, with it's own address block, then route that traffic into the main LAN (or wherever).

It's probably a better thing for security too.

Good Luck

Scott

New Member

Re: Configure DHCP on a Aironet AP 1232AG

Thanks for the input.

This is how it is currently configed.

I have my router with a secondary IP (which is for the Wireless traffice) the ap has an IP from the secondary block. I configured the AP to exclude the router (Secondary IP) and the IP of the AP but the windows server is still giveing the wireless clients IP's.

So unless you meant something else I think I am trying that with no luck.

Thanks.

Green

Re: Configure DHCP on a Aironet AP 1232AG

If I'm understanding you correctly, you have added a secondary interface (IP ADDR blah blah blah SECONDARY) address on the router interface, and the AP's address is on that address block.

First, you shouldn't need to exclude the router's address, because it should be "hard coded" and won't ask for a DHCP address.

Next, since your are not using VLANs, the clients are sending broadcast address requests, which are probably being passed by the router to the DHCP server.

If you have an "IP HELPER" statement on your router interface that is facing the wireless LAN, remove it, that will block the broadcast request and keep the request local to the AP's LAN.

If you need IP helper for the wired LAN on that interface, then you'll need to bring up a VLAN for the wireless system ... something to logically separate the broadcast domains (the wired LAN as one, the wireless LAN as the other) on the router.

You may be able to name the scope that your clients request ... but I haven't seen that implemented for a while, and I'm not sure it's still an option.

Check out the IP Helper thing and let us know.

Good Luck

Scott

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