3 Replies Latest reply on Jan 23, 2018 9:47 AM by David Smith

    NPM Alert : Cisco LAP WLC disassociation

    nwknoiz

      Hi there,

       

      I'm currently working to improve our Cisco LAP monitoring system.
      My objective is to create an alert when an AP is disassociated from the WLC's and to reset the alert when this AP's rejoin the WLC's in order to help our support team to troubleshoot this kind of issue as fast as possible.

      Our WLAN infrastructure looks like that :

       

      We have two central Cisco WLC (Primary / Secondary) used to manage AP's of multiple remote sites split into distincts AP groups.

       

      I have then created a custom alert on NPM with the following condition :

       

           if WAP IP address  contains : "site AP range" (e.g. 10.0.0.X)
           and
           if WAP status is not equal to UP

       

           Trigger action  : Log the Alert to the NetPerfMon Event Log settings

           Message : "SITE CODE" issue : ${N=SwisEntity;M=Name}  is  disassociated from ${N=SwisEntity;M=ControllerName}

       

           Reset condition : Reset this alert when trigger condition is no longer true (Recommended)

           Reset action :  Log the Alert to the NetPerfMon Event Log settings

           Message : "SITE CODE" : ${N=SwisEntity;M=Name} is associated to ${N=SwisEntity;M=ControllerName}

       

      The trigger action is working perfectly, but the reset condition is not working .
      In fact I'd like to know if the AP's has rejoined the controller, to be able to run a script or to send an E-Mail if the condition is true for more than X minutes.

      To tests the alert I've have reset one AP, I have also moved this AP from a WLC to the secondary WLC.

      In any case the reset condition didn't worked.

       

       

      Any idea ???

        • Re: NPM Alert : Cisco LAP WLC disassociation
          mesverrum

          You might try changing the no longer true reset condition to be explicitly a "WAP status is equal to UP"

          I find that sometimes the automatic resets get a little iffy.  I've never really poked inside the system to see if the WAP's are persistent objects, and dont have a wlc to check against, but another idea might be that when the LAP joins the controller solarwinds doesn't correlate the new "instance" of it to the old one, instead it might be adding it as if it were a completely new AP.  If that were the case things would get tricky.  I guess the easiest way to verify that is look at the end of the url on the AP page when it is up, should be like WLTAP:xxxx and then disconnect it, give some time to let solarwinds notice that it is gone, after your alert triggers reconnect it and see if that wltap number is the same as it was before.  If the number hasn't changed then things shouldn't be too hard to sort out.

           

          -Marc Netterfield

              Loop1 Systems: SolarWinds Training and Professional Services

            • Re: NPM Alert : Cisco LAP WLC disassociation
              nwknoiz

              First, thanks for your help .

              I’ve then tried multiple things:

              The ID is changing only when the AP is moving from a WLC to another e.g.
              On WLC#1 the ID is 111
              When the same AP is on WLC#2 the ID is 222


              This sounds quite normal as SolarWinds is gathering data from the WLC. So if the WLC differ the ID won’t be the same...


              When the same AP will come back to the WLC #1 the ID remain the same original ID (111)

              Strange things even if the APs don’t move from a WLC to another the reset condition isn’t working.
              So the ID is probably not the root cause of my issue.
              (to execute this test I’ve removed failover configuration on the test AP)

              I’ve changed the reset condition to "WAP status is equal to UP"
              It’s also not working.

              I’ve also tried to change the trigger condition to

              if WAP ID = 111
              and
              if WAP status is not equal to UP

              and do the same reset condition “reversed”:

              if WAP ID = 111
              and
              if WAP status is equal to UP

              Again the reset condition failed during the multiple tests executed.


              Strange things I’ve clicked on the message (generated from the alert) in the event log and an error popped:

               

              Unexpected Website Error

              Object WLAP:111 was not found in the database.


              (The alert NPM message is a link to the object web-page)

               

              When the AP is not associated to the WLC the object is removed from the database.
              When the AP comebacks, as said it comes with the same ID and the URL is reachable without any error (by clicking on the same alert message) as the ID remain the same...

               

              So it look like Solar Winds is removing the object from its database when the AP is no longer on the WLC and at this time the reset condition is not checked anymore (as the server can’t find the object on its database and then an error may occur) … ?

                • Re: NPM Alert : Cisco LAP WLC disassociation
                  David Smith

                  Did you get this working? I have a similar experience where the Alert triggers when I unplug the test AP it changes to Unknown state, but it doesn't change to anything else. However it does clear the alert when I plug it back in so I guess I am making some progress.

                   

                  I did remove the RemoveDissappeared check from Advanced Configuration to see if that would make a difference, and it does keep the alert now, but just as Unknown state.