Network Management

ASA/Nexus Device Has Gap In VPN Data

ASA or Nexus Devices can have gaps in VPN polling data due to a Bug in the Cisco device which improperly formats the SNMP output of IP address.

First published date

3/26/2020 11:28 PM

Last published date

9/15/2021 11:56 PM

Overview

1. Review  "How VPN monitoring works" within NPM: https://support.solarwinds.com/SuccessCenter/s/article/How-to-monitor-VPN?language=en_US

Cisco ASA and Nexus devices have a Bug which is improperly formatting SNMP data that they are creating.
You can check if you are experiencing this bug by doing an SNMP walk from your device and check if you are getting similar results to below:
(Hex-String has been removed for privacy)

This corruption occurs on OID:  1.3.6.1.4.1.9.9.171.1.3.2.1.5
This OID is suppose to be in Hex format

2. The SolarWinds.Node.ASA.Snmp.log will show the following Error message: "Couldn't resolve valid IP address from HexValue: , DotValue: . Or IP doesn't meet the validation predicates."

 

Product section

Orion Platform

Cause

When OID:  1.3.6.1.4.1.9.9.171.1.3.2.1.5
Is not in Hex format the JobEngine is unable to convert the Hex into an IP address for doing the VPN analysis.
You will find errors in the Collector service logs (\Programdata\Solarwinds\Collector\Logs\Plugins\SolarWinds.Node.ASA.Snmp.log) 
In the SolarWinds.Node>ASA.Snmp log you will find the following error:

SolarWinds.ASA.Common.Helpers.IpAddressResolver - Couldn't convert IP address from value '' using DotIpAddressConverter.
System.ArgumentNullException: Value cannot be null.
Parameter name: value
   at SolarWinds.ASA.Common.Helpers.HexIpAddressConverter.Convert(String value)
   at SolarWinds.ASA.Common.Helpers.IpAddressResolver.Convert(IIpAddressConverter converter, String value)

Error message with debug enabled:
DEBUG SolarWinds.Orion.Pollers.Framework.SNMP.SnmpManagerAdapter - out-ip: 172.17.98.55               version: 2                queryType: GetBulk        timeout: 00:00:02.5000000           error: 0 errStatus:0, errIndex:0  OIDs: 1.3.6.1.4.1.9.9.171.1.5.2.1.1.9.1575767 = OID_TYPE_STRING: b¸Ð  (0) [62B8D013]|1.3.6.1.4.1.9.9.171.1.5.2.1.1.9.1575768 = OID_TYPE_STRING: ¦±ºæ (0) [A6B1BAE6]|1.3.6.1.4.1.9.9.171.1.5.2.1.1.9.1575769 = OID_TYPE_STRING: ¦‰°Ö (0) [A689B0D6]|1.3.6.1.4.1.9.9.171.1.5.2.1.1.9.1575770 = OID_TYPE_STRING: ¦±¹û (0) [A6B1B9FB]|1.3.6.1.4.1.9.9.171.1.5.2.1.1.9.1575771 = OID_TYPE_STRING:  D
(0) [181C440E]

Alternative Errors:
ERROR SolarWinds.Orion.Collector.Plugins.Pollers.PollerResultPreProcessorBase`1 - N.VPN_SiteToSite_Status.SNMP.CiscoAsa poller result for Node 2304. Info: Failed. Polling Finished: 3/25/2020 3:37:18 AM. Error message: Couldn't resolve valid IP address from HexValue: , DotValue: . Or IP doesn't meet the validation predicates.


 

Resolution

Please search your Collector Plugin Logs (\Programdata\Solarwinds\Collector\Logs\Plugins\SolarWinds.Node.ASA.Snmp.log) and search for the following Errors:
  • Couldn't resolve valid IP address from HexValue: , DotValue: . Or IP doesn't meet the validation predicates.
  • Couldn't convert IP address from value '' using DotIpAddressConverter.
If the Above do not return any entities, search the last option and look to see if it has any of the above listed errors around it:
  • System.ArgumentNullException: Value cannot be null.
If you do not have any of the above errors listed Please contact Solarwinds Technical Support.

If you do have any of these above listed errors Please contact Cisco Technical Support to get assistance with fixing the bug your device has.