F5 interfaces monitoring (SNMP or sFlow)

In order to monitor the interfaces you can use either the MIB files which you can download from the BIG-IPs WebGUI or use the OIDs. You should be able to define that in the monitoring software.

K13322: Overview of BIG-IP MIB files (BIG-IP 10.x - 13.x)

To use the OIDs please use the following:

sys interface stat name - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.1 sys interface stat pkts in - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.2 sys interface stat pkts out - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.4 sys interface stat bytes in - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.3 sys interface stat bytes out - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.5 sys interface stat errors in - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.8 sys interface stat errors out - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.9 sys interface stat drops in - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.10 sys interface stat drops out - 1.3.6.1.4.1.3375.2.1.2.4.4.3.1.11 sys interface status - 1.3.6.1.4.1.3375.2.1.2.4.1.2.1.17 These are just some of all the different OIDs you can use. You can also run an SNMP walk on the BIG-IP to see which information you want to monitor:

Also Sevone will monitor interfaces using both SNMP or SFLOW. https://www.sevone.com/supported-technologies/f5-big-ip-monitoring-integration-guide