A tunneled protocol of an interface.
- all(1) is supported for devices which allow the setting
of thresholds on a per interface basis. This threshold is
a combined threshold for the interface which includes all
supported protocols.
- cdp(2), vtp(3), stp(4), eoam(5) and lldp(6) are supported
for devices which allow the setting of thresholds on a
per interface, per protocol basis.