1130AG dropping Lan IF

Unanswered Question
Sep 28th, 2010

We have a couple of the 1130AGs running in autonomous mode. They are POE with Cisco power injectors on the switch end. Recently it is as if they have been "disabling" their own lan interfaces.  The wireless IF stays up...mobilie users can connect to the SSID, but then never get any address from DHCP. From a wired workstation the AP does not respond to a ping. Pulling the powered ethernet cable to reset the AP does bring them back up...but it is not something we can be doing every day.

I've started monitoring the switch ports with Network Assistant to see if it is the switch that is blocking, but no data there yet. (one is attached to a cisco core switch, the other is not)

Any troubleshooting ideas out there?

Thanks, Pat W

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Elliott Shawd Fri, 10/01/2010 - 13:45

What brand/type of injector are you using? If possible, use an AC adapter to power the AP and remove the injector from the picture and test. To me, it sounds like the injector may be bad.

pweichel Thu, 10/28/2010 - 13:59

Thanks for the reply.

I was using a Cisco power injector, with the original access point power supply hooked up to it.

Recently (well yesterday), I've plugged this AP into a Cisco 3550 POE switch, and I'm still getting the same behavior...I'm just about ready to pitch this AP and find a new one! Before I do, I suppose I'll look for an IOS upgrade.

Leo Laohoo Thu, 10/28/2010 - 14:10

3550 suffers the same fate as the 2940/2950/2955.  In the AP, run the command "power inline negotiation injector".  An output will appear with the MAC address of the switch.  Follow this by the command "power inline negotiation injector ".

pweichel Thu, 10/28/2010 - 15:05

Thanks leolahoo, I assume you must have meant to pleclude that first statement with a "show" however neither  "power inline negotiation injector" nor "sho  power inline negotiation injector" give me any results...it does appear that it is a legitimate config command however. The web gui allowed me to enter that line in the config (it auto-fills the switch mac address), so we'll see where it goes from here.

I'm not finding any newer IOS...we're running 12.4(21a)JA1...perhaps there is a reason to fallback to an older version.

Thanks, PW

Leo Laohoo Thu, 10/28/2010 - 15:31

Did you try this command in "configuration" mode?  Following output is from an AP running 12.4(21a)JY.

AP(config)#power inline neg ?
  injector     Power injector is installed
  prestandard  Allow operation with prestandard high power inline devices

AP(config)#power inline neg inj
AP(config)#power inline neg injector ?
  H.H.H      MAC addr of port with power injector installed
  installed  Confirm that power injector is installed on current port
  override   Override saftey check. Force a power-injector on every port
pweichel Wed, 11/03/2010 - 10:10

I got the config set that way after your post last week. It ran fine until today 28-Oct to 03-Nov...today it dropped the LAN, yet was still powered up and advertising its SSID.  Crazy.  I shut / no shut on the switch port, it came back, then within 10 minutes, it dropped the LAN again. Maybe I need to test the cable....I'm out of ideas.

Leo Laohoo Wed, 11/03/2010 - 15:39

Can you determine WHY the interface went down?  Can you check the switch and AP logs?

pweichel Mon, 11/29/2010 - 08:04

It appears that the IOS was the culprit. We dropped this one (and another that experienced the same symptoms) from 12.4(21a)JA1 to 12.4(3g)JA1 and have gone over a week without a failure.  I'm finally feeling ready to call this "solved".


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