Unable to discover NetGuardian devices in NetOps Performance Management

Products

• Network Observability
• CA Performance Management

Issue/Introduction

Trying to discover NetGuardian TempDefender G2 and G6 model devices.

They appear to respond to SNMP requests but discovery logging shows problems with responses to hrSystem table OIDs.

Cause

The devices have snmp get-next response issues. They fail to properly respond with the sysUpTime OID.

The OID is present but only reliably returns when queried with snmp get requests.

This is a vendor device failure to properly respond to get-next requests targeting the hrSystem MIB table.

Resolution

This is resolved with a new VC that uses get instead of get-next requests for devices like this. It was resolved via DE588321, which is currently scheduled for inclusion in the 23.3.6 release.

To resolve this in releases before 23.3.6 the following VC extension can be used to work around the problem.

The following change should be made as an extension to the systemMIB VC. Setting IsKey=false for sysUpTime triggers the use of an SNMP get instead of get-next. This allows it to be read and the device to be discovered.

<DataModel xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" namespace="http://im.ca.com/certifications/snmp" xsi:noNamespaceSchemaLocation="SNMPCertificationFacet.xsd">
<Author>CA</Author>
<Version>2.0</Version>
<FacetType name="systemMib" descriptorClass="com.ca.im.core.datamodel.certs.CertificationFacetDescriptorImpl">
<FacetOf namespace="http://im.ca.com/core" name="Item"/>
    <Attribute external="true" name="sysUpTime" type="Long">
      <IsKey>false</IsKey>
      <Source>1.3.6.1.2.1.1.3.0</Source>
      <NeedsDelta>true</NeedsDelta>
    </Attribute>
    <Expressions>
     <ExpressionGroup destCert="{http://im.ca.com/normalizer}NormalizedSystemInfo" name="SystemNRMDS">
 <VCSupportExpression>sysUpTime != null</VCSupportExpression>
 </ExpressionGroup>
    </Expressions>
</FacetType>

Additional Information

For additional information see the Create or Extend Vendor Certifications documentation topic.

This change should not impact discovery of other devices. The change is only used when a device fails to return the sysUpTime OID and value with get-next.