I'm trying to add a SNMP Bandwidth sensor to a Cisco SG200 small business switch. I receive the following error:

SNMPERR_BAD_ASN1_BUILD (SNMP error # -11)

I feel like it's probably a config problem, but I need to know what causes this error in order to find out what the problem is.

Product - PRTG Network Monitor 15.2.16.2219.

Thanks for any info you can provide!

Article Comments

Hi kphillips, we appreciate your contact.
Could you please confirm, you're trying to add the SNMP Traffic Sensor?

To troubleshoot SNMP on the device, please use our Freeware SNMP Tester, run it on the PRTG Host or the host of the Probe, input the correct device credentials/address and perform a Read Device Uptime test. The Device Uptime is a critical part of SNMP and for the correct working of the Traffic Sensors, it must provide a valid result (I.E. Different than 0).

If that succeeds, you can further troubleshoot by performing a Scan Interfaces or Walk with the OID 1.3.6.1.2.1 to check if the device is providing correct responses for SNMP queries.

Please share with us the results of the walk test. (Either here or through a support ticket)

We have some troubleshooting documents that can also be helpful:
My SNMP sensors don’t work. What can I do?


Jul, 2015 - Permalink

Hi,

I am getting the exact same error when trying to add the bandwidth sensor. It started off as a different error that forced me to add custom OID 1.3.6.1.2.1.1.3.0 to my sonicwall TZ-500. below is the output from the SNMP Tester;

Walk:

----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: HYDTMAJMP01 Interface: (192.168.120.62)
12-10-2016 00:24:57 (3 ms) : Device: 192.168.120.1
12-10-2016 00:24:57 (5 ms) : SNMP V3
12-10-2016 00:24:57 (6 ms) : Walk 1.3.6.1.2.1
12-10-2016 00:24:57 (124 ms) : 1.3.6.1.2.1.1.3.0 = "127260885" [ASN_TIMETICKS]

Custom OID test:

----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: HYDTMAJMP01 Interface: (192.168.120.62)
12-10-2016 00:30:34 (4 ms) : Device: 192.168.120.1
12-10-2016 00:30:34 (6 ms) : SNMP V3
12-10-2016 00:30:34 (8 ms) : Custom OID 1.3.6.1.2.1.1.3.0
12-10-2016 00:30:34 (241 ms) : SNMP Datatype: ASN_TIMETICKS
12-10-2016 00:30:34 (244 ms) : -------
12-10-2016 00:30:34 (246 ms) : Value: 127294553
12-10-2016 00:30:34 (248 ms) : Done

But everytime i try to add the sensor i get the same error "SNMPERR_BAD_ASN1_BUILD (SNMP error # -11)"


Oct, 2016 - Permalink

Hello riyengar,
thank you for your post.

Please confirm, is HYDTMAJMP01 / 192.168.120.62 PRTG's Server or the address of the probe that will poll this device?

The SNMP Tester confirms that the OID is valid/available on the 192.168.120.1 system. As you're using SNMP V3 please head to the Settings of the Device in PRTG and make sure that the Credentials perfectly match the credentials that you've used in our SNMP Tester, our SNMP Tester and PRTG are built around the same SNMP Engine/Components, this means that if it works in the tester it MUST work in PRTG as well.

Please make sure that you're running the LATEST available/released version of PRTG for best results.

Best Regards,
Luciano Lingnau [Paessler Support]


Oct, 2016 - Permalink