Fortigate software switch interfaces break interface-usage

[0xliam]

Hi,

I have a FortiGate firewall with a Software Switch configured - it appears this is breaking interface-usage and other commands for retrieving interface checks:

I am able to query all other interfaces, e.g.:

[root@satellite plugins]# '/usr/lib64/nagios/plugins/check_nwc_health_new' '--community' 'xxxx' '--hostname' 'xxxx' '--mode' interface-usage --name 170
OK - interface  170 (alias wireless.) usage is in:0.00% (0.00bit/s) out:0.00% (0.00bit/s) | ' 170_usage_in'=0%;80;90;0;100 ' 170_usage_out'=0%;80;90;0;100 ' 170_traffic_in'=0;0;0;0;0 ' 170_traffic_out'=0;0;0;0;0

If I query interface 171 I receive:

[root@satellite plugins]# '/usr/lib64/nagios/plugins/check_nwc_health_new' '--community' 'xxxx' '--hostname' 'xxxx' '--mode' interface-usage --name 171
UNKNOWN - Mode interface-usage is not implemented for this type of device

I also receive the same error if no interface is specified.

If I run snmpwalk for the ifType it returns:

IF-MIB::ifType.171 = INTEGER: bridge(209)

I've attached the snmpwalk output as per troubleshooting steps.

Any suggestions how to mitigate this issue would be greatly appreciated.

snmpwalk_check_nwc_health_new_10.85.2.254.txt

EDIT:

Please ignore the plugin name - was testing with the latest version to see if that fixed it.