I moved up to ADSL recently and it's quite nice, but I miss one thingabout my old Supra modem: I've been spoiled by its luxurious front paneldisplay. The front panel of my ADSL modem is somewhat of a letdown andI've been missing information that I used to be able to get at a glance,in particular how saturated my link is.

The ADSL modem has four front-panel LEDs, all equally prominent:

Power ADSL DATA LAN

(DATA is on if the DSL

We have a number of internal networks here . One of them is a port-isolated subnet forgeneral user machines (such as Windows laptops), where the port isolationmakes sure that user machines can't talk to each other and thus can'tinfect each other. One day, an alert user on the port isolated networkreported to us that his machine was seeing packets from the outsideworld destined for a completely different machine.

(One of the cool things about working in a Computer Science departmentis that

Traditional sockets implementations have an irritating limitation, atleast for TCP sockets: it is impossible to gracefully and cleanly shutdown listening (server) sockets.The problem is that kernels accept new TCP connections for listeningsockets without asking your server; accept() doesn't actually accept the connection, it just gives you the next one that the kernel hasalready accepted on your behalf.

This means that to shut down cleanly,you need a two-stage process: first you tell the kernel to stop acceptingnew connections