current-users: Idle time on network interface... Can we tell?

Subject: Idle time on network interface... Can we tell?
To: None <current-users@NetBSD.ORG>
From: Peter Seebach <seebs@solon.com>
List: current-users
Date: 12/02/1995 17:18:00

Is there a way to determine whether an interface is idle?  Some of our
users occasionally line camp.  Unfortunately, since the tty is idle during
an entire PPP or SLIP session, we can't just check for idle time.  :(

-s