SNMPv2 Device is picking SNMPv1 for polling

[Praveen Venkatesan]

I see some of the devices are picking SNMP v1 version although the device is SNMPv2 supported , Either i need to  change the SNMP-GET version from SNMPv1 to SNMPv2c in Device admin page .Why this issue is occurring it is due to bulk SNMP request whether v2 is not able to manage ? 

I saw a similar issue before 3.0 series issue . Whether 3.7 is also affected ?  Can I forcefully restrict the v1 communication from DC ?

SNMPv2 discover fails due to use of get-bulk SNMP request (broadcom.com)

Symptom:

 When discovering SNMPv2 devices, 

DX NetOps Performance Management

 always sends SNNPv1 queries in the discovery. This can cause some problems in the network that SNMPv1 is restricted, such as the data collector host would be blocked from access the devices.

Resolution:

 With this fix, the 

DoNotUseSNMPv1

 global boolean configuration attribute has been added on facet 

DiscoveryDefaultConfig

, with a default value of false. When it is set to true, SNMPv1 queries will not send out from any data collectors. You can update this attribute using the data aggregator REST Put query with URL 

rest/discoverydefaultconfig

.

(21.2.7, DE521140, 32923236)

[Jeffrey Pinard]

That setting is brand new to 21.2.7+.  So you'd need to move to 21.2.7+ to use it.

Check dcdebug discovery logging when doing device discovery/rediscovery.
Was it able to see V1 and V2 show SUCCESS?

Note: if the current profile works, we do not change to a diff profile on discovery.  You would to manually need to change SNMP version or profile in Monitored Devices or DA REST for the device.

[Praveen Venkatesan]

Hi Jeffrey,

But the device responds to SNMPv2c already  why it is picking V1 . In case the there is any issue in responding to v2 only it should pick V1 as per product design.  Whether can i change SNMP GET version to v2c using Rest ?  

Was it able to see V1 and V2 show SUCCESS? -> I cant able to see any entries related to V1 and V2C in discovery logs 

[Jeffrey Pinard]

If there was an issue validating SNMP v1 and v2 version of the same community string, and only v1 responded during the 3 secs, then we'd choose v1 over v2 for the device.  After that until v1 no longer works, we would stick with it unless someone manually changed it.

The discovery log only is so big, and if it's logging other stuff, the profile discovery lines may have been dropped after some amount of logging is stored.