FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
Dongfang_Li_FTNT
Article Id 329611
Description

This article describes a possible cause for the error 'SNMP general error' seen in debug when SNMPv3 is used.

Scope FortiOS
Solution

This error is shown when there are certain parameters missing that prevent the SNMP transaction to complete.

One of them may be the outgoing interface. After setting up SNMP monitoring to the FortiGate management interface, packet captures at the egress interface may show that FortiGate is not responding to SNMP queries (no reply sent out). Running an SNMP debug will show an SNMP general error.

 

diagnose debug reset

diagnose debug application snmpd -1

diagnose debug enable

 

snmpd: usm scopedpdu parse: no varbinds.
snmpd: v3 recv: parse failed. errno=-1 (snmp general error)

image.png

 

The management interface is reserved in the FortiGate HA cluster management interface configuration.

The SNMP polling is done over this interface. But to make it work for SNMP over this interface, the ha-direct option must be enabled both in system ha config and in the system snmp user config.

 

config system ha

set ha-direct enable 

end

 

config system snmp user

edit snmpv3-user

set ha-direct enable

next

end

 

Related article:

Troubleshooting Tip: General troubleshooting guide for SNMP issues