topic Re: APs missing from WLC in Wireless

APs missing from WLC

pt_wang — Sat, 03 Jul 2021 23:57:00 GMT

My customer who has one WLC4402,36 AP1130.Some of APs miss from WLC sometimes but I can ping those APs at this time.I can not find any messages from WLC(version 4.2.61).Any suggestions?

Re: APs missing from WLC

dennischolmes — Wed, 07 Jan 2009 13:02:47 GMT

Does he have a 4402-50. If not he has exceeded the number of APs supported by the controller. The 4402 comes in 12, 25, and 50 AP versions. The 4404 is 100 AP controller. If the 4402 is a 50 then insure that trunking is enabled on the ports where the APs missing reside. The APs will grab dhcp from any available dhcp server but if option 43, DNS, or manual controller location is not enabled, the APs will not see the controller.

Re: APs missing from WLC

gjcluttrell — Thu, 08 Jan 2009 00:19:50 GMT

Dennis, you are the man! You answered one of my questions before I posted it, thanks. We love doing business with your company! Talk to you soon.

Re: APs missing from WLC

dennischolmes — Thu, 08 Jan 2009 12:42:48 GMT

Quite glad to help man.

Re: APs missing from WLC

gjcluttrell — Thu, 08 Jan 2009 23:06:24 GMT

Is this WLAN running layer 2 or layer 3 mode? I had a similair issue when adding new APs & they were not recognized by the controller until I bumped up to layer 3 mode & configured AP manager on the controller.

Re: APs missing from WLC

dennischolmes — Fri, 09 Jan 2009 17:22:15 GMT

You should always be running layer 3 mode as Cisco is phasing out support for layer 2. Layer 3 has more robust support for third party client devices and applications and actually treats wireless as an extension of the IP network.

Re: APs missing from WLC

pt_wang — Sat, 10 Jan 2009 02:20:45 GMT

The 4402-50 has 50 AP versions, less than 50 APs.

APs was working, but some of them it was missing sometimes.Those APs ping is works.

My customer told me he disble/enable the Linksys POE ports, then the APs come back,

Re: APs missing from WLC

pt_wang — Sat, 10 Jan 2009 02:25:25 GMT

Layer 3 mode, The APs was working, but some of them missing sometimes but ping those APs works.My customer told me he enable/disable

the Linksys POE ports then those APs back to works.

Re: APs missing from WLC

gjcluttrell — Sat, 10 Jan 2009 14:46:15 GMT

You mentioned you was using a PoE switch. It would be interesting to see if the same thing happens if you use power injectors on the APs. On the 1130 APs, if you're using a PoE switch, if loopback detection is not enabled on the switch port the AP is plugged into, the AP will cause a loopback on your switch/LAN which would cause it to loose connectivity. Let us know if this helps.

Re: APs missing from WLC

pt_wang — Sun, 11 Jan 2009 11:56:06 GMT

How I enable loopback detection on Linksys 20xx series switch?

Re: APs missing from WLC

gjcluttrell — Sun, 11 Jan 2009 13:51:55 GMT

I'm not sure on that particular switch, it may not have that feature. You'll probably have to use a power brick for AP power.

Re: APs missing from WLC

dennischolmes — Sun, 11 Jan 2009 17:29:15 GMT

Does that switch also support CDP? If so, try turning CDP off if possible. CDP enabled causes a problem with PoE methodology which might be why they reappear after you turn PoE off.

Re: APs missing from WLC

pt_wang — Mon, 12 Jan 2009 01:57:36 GMT

Linksys switches does not support CDP now.

Re: APs missing from WLC

Leo Laohoo — Wed, 14 Jan 2009 05:17:35 GMT

If an AP refuses to join the Wireless LAN Controller, type the following command:

lwapp ap controller ip address

Re: APs missing from WLC

m-geisler — Fri, 30 Jan 2009 23:14:22 GMT

How many APs and PoE devices are on the switch?

My experience is that some APs (especially those with a-radios) do not get enough power from the switch. So you can ping them but the radios won't work.

Sometimes they work fine until one additional PoE device goes online and that messes it up.

try power cords/injectors on some APs or reduce the load on the switch.

Does the switch has an UPS? HOw reliable is the powergrid in your area?

Good luck

Michael

Re: APs missing from WLC

dennischolmes — Sat, 31 Jan 2009 00:02:47 GMT

That's all well and good if the controller can be pinged. What is usually the case here is that there is no route to the management interface of the controller or the ap manager interface as well. Check to see if there are IP address conflicts with those two interfaces. Next, make sure that you have not exceeded the total number of APs per physical interface. If you have add a LAG group or a second ap management interface. Verify security certificates are on the APs and that the date and time on the controller is accurate. Lastly, make sure you have no PoE issues or CDP. You're beating a dea horse here guys.