Technical Tip: Troubleshooting steps for SNMP queries timing out

Description

This article describes the troubleshooting steps needed to check if SNMP queries from the SNMP server to FortiWeb are timing out.

Scope

FortiWeb.

Solution

Troubleshooting steps needed to take if the SNMP walk fails from the OpManager/SNMP manager.

snmpwalk -v2c -c 'SNMPtest' 192.168.100.1 1.3.6.1.2.1.1.5.0 Result: Timeout: No Response from 192.168.100.1

1. Take Packet captures on the SNMPManager and validate if the request is forwarded to the FortiWeb interface.

2. On FortiWeb, validate the interface used for SNMP and check if SNMP is enabled in the interface settings or not.
   
   

3. Ping from FortiWeb to the SNMP manager and Vice-Versa to do a basic connectivity check. Do not completely rely on this, as sometimes the ping could be disabled in the network settings.
   
   

4. Take Packet captures on FortiWeb to determine if packets are getting received on the interface or not. To do so, follow this document: Packet capture via Web UI.
   
   

5. If packets are going out of the SNMP manager and not getting received on FortiWeb, then there is a routing or Firewall in the middle that is blocking the connection.
   
   

6. Another condition can be if there is a firewall in between that is doing NATting, and FortiWeb does not see the source IP of the SNMP manager, so it will not be matched with the allowed host, and hence the connection will not form.
   
   

   

Note: If the above steps are correct and still it's not working as expected, then open a ticket with Fortinet Support and include all the details with packet capture and config file.