I just wrote:

> Internally, you presume your users are to be trusted. Externally, your
>  private address space IP addresses that constitute your LAN are invisible
to
>  the rest of the world (indeed, they're not even unique to you; thousands of
>  sites can be using exactly the same addresses).
>
>  If you let someone through your router because he has the passwords, then
>  you've made him a trusted member of your family of users. Otherwise, he
> could never see your printers.

Let me write an addition to what I just wrote.

You may actually have two IP addresses for some or all of your printers, your
private address space IP addresses (10.x.x.x) *and* some real-world IP
address, assigned by virtue of the fact that you have entered these private
IP addresses into a NAT (network address translation) table in your router.

In that case, the rest of the world can see your printers. There's nothing
wrong with that, if you need to do it. In fact, I've been thinking about
putting one or two of our printers on-line. However, just to keep down the
hooliganism of the intellectually bored, you should (must) assign
administrator passwords to all of the printers that you've opened up to the
world. The newest printers have an HTTP server built into them, so that you
can perform all system management tasks using a web browser. The older
printers have to be addressed using telnet.

To find out if your printer does support HTTP, simply type on your browser:

           http://192.168.1.100

(or whatever the address of your printer is). If it doesn't support HTTP, it
will tell you. If it doesn't, telnet into the printer using your favorite
terminal emulator. Virtually all network capable printers support telnet
administration.

Wirt Atmar