On Sat, 25 Aug 2001, L.D. Best wrote:
> Lars,
>
> If you're on a cable modem, your ISP should have the firewalls in place.
Highly doubtful.
> >From what I understand, even having a "real" IP like I do is rather rare
> on most setups.
What's rare is that your cable company has you
behind a firewall.
Most cable companies give you an IP without any firewall.
My SB3100 contains an internal web server for
configuration tasks. IOW, I can type 192.168.100.1
(the internal URL for the modem) and get information
from it, and reset it, etc.. These web pages hint at
additional functionality, so it's possible that Lars,
having the SB4100, might well have firewall capability
within the modem itself.
From the cable-modem's web server:
Acquire Downstream Channel
Done
Obtain Upstream Parameters
Done
Establish IP Connectivity using DHCP
Done
Establish Time Of Day
Done
Transfer Operational Parameters through TFTP
Done
Register Connection
Done
Initialize Baseline Privacy
Skipped
Hmmm... I wonder why it "skips" baseline privacy...
And then there's this:
DHCP Server Enabled
The SURFboard cable modem can be used as a gateway to the Internet by a
maximum of 32 users
on a Local Area Network (LAN). When the Cable Modem is disconnected from
the Internet, users
on the LAN can be dynamically assigned IP Addresses by the Cable Modem
DHCP Server. These
addresses are assigned from an address pool which begins with
192.168.100.11 and ends with
192.168.100.42. Statically assigned IP addresses for other devices on
the LAN should be chosen
from outside of this range
It's also *possible* that your firewall resides
within your cable modem, and that it's configurable.
> And IIRC you have to have a "real" xxx.xxx.xxx.xx IP to
> even have to worry about people getting through to you.
No, if your firewall can be cracked, then the
internal machine/network is just as open as if there
was no firewall at all. A firewall isn't, by itself,
assurance of security. It's just another layer of many
which goes towards security.
> Just thought you might want to do a bit more homework before spending
> money you may not need to spend.
Yes, before you do anything else, Lars, ask what the
URL of your cable modem is. (probably the same as mine,
192.168.100.1) Look through the web pages on it, and
you just might discover it's already a firewall and
router.
- Steve
