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Cisco AP Signal Strength

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Hello, I would appreciate a little help setting up a custom SNMP sensor to monitor signal strength on a Cisco 1532E wireless bridge device. I went through and found the OID and created the oidlib via the MIB Importer. I then saved it to \snmplib. So, I think I'm good there. I first tired to create the sensor, I used a Custom Sensor - SNMP Custom sensor type and put in the OID I found in the MIB (1.3.6.1.4.1.9.9.273.1.3.1.1.3). But, I got SNMP error #223. Basically, it didn't know what I was asking for. So, I downloaded the SNMP Tester and did a Walk of the OID listed previously. Here are the results:

----------------------- New Test -----------------------

Paessler SNMP Tester 5.2.3 Computername: CDCMS130 Interface: (10.1.4.30)
8/10/2016 12:21:30 PM (1 ms) : Device: 10.1.75.10
8/10/2016 12:21:30 PM (1 ms) : SNMP V2c
8/10/2016 12:21:30 PM (2 ms) : Walk 1.3.6.1.4.1.9.9.273.1.3.1.1.3
8/10/2016 12:21:30 PM (4 ms) :1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.9.67.68.67.66.114.105.100.103.101.240.178.229.221.98.32 = "-66" [ASN_INTEGER]

See that "-66" listed at the end? That's the number I want to display in my monitor. That's the same number you get if you run "show dot11 associations all-client" on the WAP.

NOW, here's the issue: When I put that big long OID in the "Custom OID" field in the SNMP tester, I get this:

----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: CDCMS130 Interface: (10.1.4.30)
8/10/2016 12:24:13 PM (1 ms) : Device: 10.1.75.10
8/10/2016 12:24:13 PM (1 ms) : SNMP V2c
8/10/2016 12:24:13 PM (2 ms) : Custom OID 1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.9.67.68.67.66.114.105.100.103.101.240.178.229.221.98.32
8/10/2016 12:24:13 PM (5 ms) : SNMP Datatype: ASN_INTEGER
8/10/2016 12:24:13 PM (6 ms) : -------
8/10/2016 12:24:13 PM (7 ms) : Value: 4294967230 (OK)
8/10/2016 12:24:13 PM (8 ms) : Done

That Value (4294967230) is somehow related to the -66 value I received above. I want to display -66 in the monitor (or 66 would also be fine). I tried just dividing the two numbers and I got 65075261. I found that I could display 66 in the monitor if I put this in the Divide field. But, I'm not sure that's actually right.

Here's why: A wireless bridge is two sided meaning there's two AP's connecting the buildings. When I try to do the same thing on the other side, I don't get the same 65075261. I run the Walk on the other side and get -69. When I then run the Custom OID I get 4294967227. A simple division yields 62245901. Since this number does not match the 65xxxx number from above, I can only assume that this is not a correct way to determine the value I"m looking for.

SO....How does one get the correct value to appear in the monitor?

cisco-ap custom-snmp-sensor mib-importer snmp-tester

Created on Aug 10, 2016 5:40:01 PM by  sbemister (0) 1

Last change on Oct 19, 2016 4:46:39 AM by  Luciano Lingnau [Paessler]



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Hello there,

Very good investigation so far on your end :)

It should work with the SNMP Custom Sensor by setting Value Type to Gauge (signed integer) in the sensor's settings, because the standard setting (Integer) is not for negative values so it changes its representation.

Kind regards.

Created on Aug 12, 2016 11:06:37 AM by  Erhard Mikulik [Paessler Support]

Last change on Aug 12, 2016 11:12:23 AM by  Erhard Mikulik [Paessler Support]



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Ah HA! That did it. Thank you very much!

Created on Aug 12, 2016 1:37:25 PM by  sbemister (0) 1



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