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How can I see all interfaces when adding an SNMP sensor for my Cisco device?



I added a Cisco router (switch) as device in PRTG. When I try to add an SNMP sensor (e.g. SNMP Traffic sensor) to it, some interfaces/counters are missing. Entries for ethernet and serial port are missing.

Or: I get an error message saying « No Such Name (SNMP error # 2) ».

What can I do to see all interfaces of my device?

cisco installation prtg router sensor snmp

Created on Feb 10, 2010 2:00:05 PM by  Daniel Zobel [Product Manager]

Last change on Apr 16, 2010 11:21:07 AM by  Daniel Zobel [Product Manager]

2 Replies

Accepted Answer



This article applies to Network Monitor 12 or later, as well as to previous (deprecated) versions

Enabling 32-Bit Counters for Cisco Routers

For some reason, sometimes Cisco routers do not show certain interfaces unless you force 32-bit counters. To do so, please follow these steps:

  1. In the PRTG web interface, choose your Cisco device from the device tree.
  2. Select the Settings tab.
  3. Scroll down until you see the SNMP Compatibility Options entry.
  4. Uncheck inherit from .... You can now change the compatibility options.
  5. In section 32-bit/64-bit Counters, select the option Use 32-bit counters only (see screenshot below).
  6. Click on Save.
  7. Add the sensor anew.
  8. Adding the counters should now work.
  9. Please remember to turn off the 32-bit option (i.e., choose Use 64-bit counters if available) after adding the sensor.

Note: If a lot of traffic is going through your the 32-bit interface, please make sure you select a small scanning interval to prevent a 32-bit overflow in your device. An overflow would cause your device to overwrite its own monitoring data before it is sent to PRTG and therefore lead to incorrect data. A 32bit counter can store a maximum of 2^32 bytes.

SNMP Compatibility Options of PRTG

SNMP Compatibility Options of PRTG

Created on Feb 10, 2010 2:16:23 PM by  Daniel Zobel [Product Manager]

Last change on Nov 15, 2013 1:51:28 PM by  Gerald Schoch [Paessler Support]



This solution also works for routers with a lot of interfaces, where the "higher" interfaces are showing up when scanned, but will not show/report any data and have state "Down" after being added.

Great tip!

Created on Sep 30, 2010 10:12:44 AM

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.