Tracing Operations of an Individual Router or Switch Interface
To trace the operations of individual router or switch interfaces, include the traceoptions statement at the [edit interfaces interface-name] hierarchy level:
You can specify the following interface tracing flags:
all—Trace all interface operations.
event—Trace all interface events.
ipc—Trace all interface interprocess communication (IPC) messages.
media—Trace all interface media changes.
The interfaces traceoptions statement does not support a trace file. The logging is done by the kernel, so the tracing information is placed in the system syslog files.