FortiOS 7.4.8 – BGP Session Monitoring Issue with Nagios

[heldproducer]

Hi everyone,

We are currently using check_bgp.pl from Nagios Exchange to monitor BGP session states on a FortiGate firewall. Previously, this setup worked correctly on FortiOS 7.2.10.

Due to some firewall issues, we recently upgraded the device to FortiOS 7.4.8. Since the upgrade, Nagios is no longer able to monitor BGP sessions using check_bgp.pl. All checks now return the same error message: “no such instance.”

We have tried adjusting the command and testing alternative checks, but the issue persists regardless of the approach used.

Has anyone experienced similar problems monitoring BGP state on FortiGate devices after upgrading to FortiOS 7.4.x?
Any advice, workarounds, or confirmation of changes in SNMP/BGP behavior would be greatly appreciated.

Thanks in advance!

[Kindya]

Have you tested with a full SNMP walk on the BGP tree to see whether the FortiGate is still exposing the same MIB objects?