Technical Tip: When interfaces are deleted they are not removed from the monitor-bandwidth list

[yangw]

Description	This article describes the error 'Maximum number of monitored interfaces reached' that appears when enabling bandwidth monitoring on a new interface even if the configured interfaces do not reach the maximum number.
Scope	FortiOS v7.2.8.
Solution	Adding a new Interface Bandwidth widget on the Dashboard for a new interface, the following error will be displayed: Failed to enable bandwidth monitoring for specific interfaces. Maximum number of monitored interfaces reached. The command 'diagnose debug traffic interface' can be used to check the monitored interfaces. The result above displayed 25 interfaces (maximum number) that have been configured for bandwidth monitoring, however, only 14 interfaces were configured (it does not even reach the maximum) which can be checked through the command below. show | grep -f monitor-bandwidth The following command can also be run to verify the number of interfaces that have monitor-bandwidth enabled on firewall.       show system interface | grep -c monitor-bandwidth The issue could be the configured interfaces reached the maximum number in the past when interfaces are deleted they are not removed from the monitor-bandwidth list. The issue has been reported as a bug and that is fixed in FortiOS v7.2.11. The workaround is to create an interface with the same name as the previously deleted interface, enable/disable the bandwidth monitoring, and then delete the interface. Related article: Technical Tip: How to check interface bandwidth utilization from GUI