topic Re: WLC and LWAP initial setup in Wireless

WLC and LWAP initial setup

bevans — Sat, 03 Jul 2021 21:31:11 GMT

I am having some issues with the initial setup of a 4402 WLC and 35 Cisco Aironet LWAPPs. The WLC and the LWAPPs are configured in the same VLAN and a DHCP server is setup to serve the VLAN. The WLC is configured for LAYER2. The LWAPPs show link light on the switches they are plugged in to... but I cannot see them from the WLC. Any thoughts?

Re: WLC and LWAP initial setup

fynskisb16 — Wed, 22 Aug 2007 16:54:07 GMT

Try setting your WLC to layer 3 mode.

this is from the WLC guide 4.1 page 1.5

The requirement for Layer 2 LWAPP communications is that the Cisco Wireless LAN Controller and

Cisco 1000 series lightweight access points must be connected to each other through Layer 2 devices on

the same subnet. This is the default operational mode for the Cisco Wireless LAN Solution. Note that

when the Cisco Wireless LAN Controller and Cisco 1000 series lightweight access points are on

different subnets, these devices must be operated in Layer 3 mode.

The requirement for Layer 3 LWAPP communications is that the Cisco Wireless LAN Controllers and

Cisco 1000 series lightweight access points can be connected through Layer 2 devices on the same

subnet or connected through Layer 3 devices across subnets. Another requirement is that the IP

addresses of access points should be either statically assigned or dynamically assigned through an

external DHCP server.

Re: WLC and LWAP initial setup

bevans — Wed, 22 Aug 2007 17:46:23 GMT

Thank you for your post.

Howerver, I do not see the need to set the WLC to LAYER3. From what I understand LAYER3 mode is for when the WLC and the APs are in different VLANs. This is not the case for my installation. Everything will be in one VLAN; no routing needed.

Am I missing something? Thanks again.

Re: WLC and LWAP initial setup

fynskisb16 — Wed, 22 Aug 2007 19:32:43 GMT

Are the AP's in the same vlan as the management interface on the WLC? If they weren't you should make the WLC Layer3.

Re: WLC and LWAP initial setup

bevans — Thu, 23 Aug 2007 11:36:37 GMT

Thank you for your post. Yes they are in the same VLAN. So, I do not see the need for LAYER3. Any other thoughts?

Re: WLC and LWAP initial setup

ericgarnel — Thu, 23 Aug 2007 12:27:55 GMT

You will need L3 if you want to support multicast on the controllers.

Re: WLC and LWAP initial setup

bevans — Thu, 23 Aug 2007 12:33:23 GMT

For what reason would I need to support multicast? Also, I did try putting the WLC in LAYER3 mode and assigned an addtional IP to the unit. Still no go.

Anything else? Thanks!

Re: WLC and LWAP initial setup

ericgarnel — Thu, 23 Aug 2007 12:41:50 GMT

ummm... to support multicast to wireless clients. If you don't need to provide multicast to your wireless clients, definitely disable it (multicast).

Are the Lwapp APs in the same vlan as the management interface of the controller?

Re: WLC and LWAP initial setup

bevans — Thu, 23 Aug 2007 13:39:29 GMT

Yes. They are in the same VLAN.

Re: WLC and LWAP initial setup

steve.busby — Thu, 23 Aug 2007 16:49:02 GMT

Can you verify you followed the following document to setup your WLC and LWAPPs?

http://www.cisco.com/en/US/products/hw/wireless/ps430/products_configuration_example09186a0080665cdf.shtml

If the WLC does not see the LWAPPs, then check that your DHCP server has option 43 correctly configured.

HTH

Steve

Re: WLC and LWAP initial setup

bevans — Thu, 23 Aug 2007 17:50:40 GMT

Again, thank you all for your posts.

I did follow that doc step-by-step for my initial setup. I did not set the DHCP Option 43 for this reason as per the doc:

Note: Option 43 is used if the APs reside in a different subnet.

And, as I stated the APs are NOT in a different VLAN/segment.

Any other thoughts?

Re: WLC and LWAP initial setup

ericgarnel — Thu, 23 Aug 2007 18:02:53 GMT

Ok, so you have the ports on the controller connected to switchports that are set to trunk in 802.1q and you have the lwapps plugged into switchports in the same vlan as the management interface on the WLC and the switches are in the same vtp domain. The APs should see the controller without any issue. There was another thread in the wireless group in which the engineer received the autonomous APs instead of the lwapp APs which seems easy to given the similarity of the part #s.

Put a sniffer on the wire and capture soem traffic. Also, on the WLC, type in "debug lwapp events" + 'debug lwapp errors' and you should see a bunch of messages with the word "SPAM" in them

Re: WLC and LWAP initial setup

bevans — Thu, 23 Aug 2007 18:38:55 GMT

Thank you for your post eric. My config is as follows...

Switch port that the WLC plugs in to (CatOS):

set vlan 203 3/4

set port name 3/4 WLC Mgmt Port

set trunk 3/4 off dot1q 1-1005,1025-4094

Switch port that the LWAPP plugs in to (IOS):

interface FastEthernet0/9

description Cisco LWAPP

switchport access vlan 203

spanning-tree portfast

Is there something that I am missing there? I am certain that the APs are the correct model. Thanks!

Re: WLC and LWAP initial setup

steve.busby — Thu, 23 Aug 2007 19:44:40 GMT

Thank you for including the port configuration. Make the switch port your WLC plugs into a trunk port (802.1Q) allowing VLAN 203.

Re: WLC and LWAP initial setup

bevans — Fri, 24 Aug 2007 12:15:17 GMT

Thank you! Setting up the trunking properly on the port the WLC connects to got me a little further. Now, once reset, I can see the APs doing a 'show cdp neighbor' command.

However, the APs are not getting IP addresses from my DHCP server. Do I need to be concerned with the OPTION43 and OPTION60 settings on my DHCP server?

Thanks again.

Re: WLC and LWAP initial setup

ericgarnel — Fri, 24 Aug 2007 12:31:02 GMT

Put the controller in Layer3 mode & reboot and they should start getting ips. I did this back in 3.2x code, maybe it has changed in 4.1.x, but that was how I was able to get ip addrs assigned to the APs.

Re: WLC and LWAP initial setup

steve.busby — Fri, 24 Aug 2007 14:20:42 GMT

In your original post you stated "...a DHCP server is setup to serve the VLAN...". Is the DHCP server actually in VLAN 203? If not, then you will need an IP helper address on your Layer 3 interface for VLAN203 which points to the DHCP IP address.

Provided your LWAPPs and WLC are both in the same VLAN, you shouldn't need to use DHCP Option 43. But it won't hurt to include it for some extra insurance.

HTH

Steve

Re: WLC and LWAP initial setup

bevans — Fri, 24 Aug 2007 17:07:14 GMT

Thanks for your post.

The DHCP server is not in the same VLAN. The ip-helper is configured. When I reset one of the APs I see it come up (in show cdp neighbors) and then disappear after a short time. It never recevies an IP. However, a laptop/PC will. Any thoughts?

Re: WLC and LWAP initial setup

jwadleigh — Fri, 24 Aug 2007 17:13:46 GMT

Hi!

You shouldn't need either option 43 or 60 for DHCP, given your configuration. Also, you won't need to convert to L3 operation.

It sounds like the real problem here is with your AP's not receiving a DHCP response. Of course, IP connectivity is a prerequisite for LWAPP Discovery.

Here are a few things to look at:

1.) Is the DHCP server in the same network (VLAN203)? If not, is the appropriate helper address provided on the gateway?

2.) Is there a DHCP scope established for VLAN203? Confirm that the addresses are in the right network, that the subnet mask is correct, and that the default gateway also corresponds to the subnet.

3.) Is the DHCP server receiving the request? Maybe a trace would shed some light.

Hope this helps! Good luck, and let us know how you did!

Re: WLC and LWAP initial setup

bevans — Fri, 24 Aug 2007 17:29:20 GMT

Thank you... I found a silly error on my part. However, the APs are still not registering. I have reset the APs and the WLC and the APs now have IP addresses but will not register. I can ping the APs but that is it. Any thoughts?