Re: One computer two different networks

[Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>]

On 2006-10-10 Santiago Barahona wrote:
> We have about 250 computers that are isolated in a high-security
> network, we want to give internet access to those computer users
> without compromising the secured network...of course our first thought
> is to buy 250 computers so the users can switch between computers (one
> for the secure network, one for internet)... but that might not be
> most practical solution...
>
> So, I've been looking around and I've found a product called DATAGATE,
> from Tenix which works as a "Data Diode"... looks interesting... but
> I'd like to have a second opinion...
>
> Does anyone know about other products or techniques on how to
> accomplish this??

One way to accomplish this is to implement a so-called graphical
firewall.

Have a network setup like this:

  Internet --- FW1 --- DMZ --- FW2 --- LAN

LAN is where your 250 computers reside. Into the DMZ you put a terminal
server with web browser, mail client and whatever other program you want
your users to access the Internet with. Make sure the terminal server is
hardened.

Configure FW1 to:
- ALLOW access FROM the terminal server in the DMZ TO the Internet
- DENY access FROM the Internet TO the DMZ (except for related traffic)

Configure FW2 to:
- ALLOW remote-desktop access FROM the LAN TO the terminal server only
- DENY access FROM the DMZ TO the LAN (except for related traffic)

For Windows Terminal Services remote-desktop access would be through
port 3389. Make sure you have only the remote desktop and maybe the
clipboard, but no mapping of printers, shares, or other resources.

Keep the remote-desktop client on your LAN computers up-to-date.

Regards
Ansgar Wiechers
-- 
"Another option [for defragmentation] is to back up your important files,
erase the hard disk, then reinstall Mac OS X and your backed up files."
--http://docs.info.apple.com/article.html?artnum=25668

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