Firewall/Router for Sharing a Cable Modem Connection
A while ago I built a debian firewall from an old 486 which, by virtue
of NAT, my Win98 PC hid behind. I didn't get as far as using dial on
demand but that was my next step. I have now moved to an area covered
by cable broadband provided by Blueyonder in the UK. I am inclined to
sign up for this and rebuild my debian firewall to suit. I know I could
use something like SmoothWall but like to understand some of what goes
on 'under the bonnet'. I found building my first firewall a great
introduction to GNU/Linux in general, debian and networking.
If anyone has had any good/bad experiences with this I would be grateful
for them.
Also I have a few queries which I'd be grateful for help with:-
1. The set up will be as follows, I use greek letters for naming
purposes at the moment:-
/ Beta(W98 Desktop)
Internet---Cable Modem---Alpha(Firewall/Router)---Hub- Gamma(Debian
Desktop)
| \ X Terminals etc
Omega (Experimental
Web Server) etc
Is it correct to call Alpha a Firewall/Router? I gather it will get its
external IP address dynamically. I will use NAT to hide the 10.X.X.X
internal addresses.
2. What packages do I need over and above those I am familiar with for
my old dial-up set-up? I am thinking mainly of DHCP which I believe is
necessary as I will have a dynamic external IP address. I think I will
write the iptables rules by hand. I used ssh in my previous set-up to
login to the firewall internally which worked well so I will do that
agin and make sure telnetd isn't on the machine.
3. Is a 486 up to the task? I believe the download rate is up to 512K.
4. How can I install Woody with a 2.4 kernel from my CD set? The
default seems to be a 2.2 kernel. I don't understand the instructions
on the CDs or those I've found on the internet. I believe I need 2.4 to
use iptables.
5. I want to get emails generated by Alpha (containing logfiles etc)
delivered via an email address provided by the cable provider *or*
internally. Am I correct in thinking exim can do both of these
alternatives? Apologies if I am straying 'off list' here.
6. Does iptables enable the use of things like ICQ and gaming over the
internet 'out of the box' without the workrounds necessary when using
ipchains?
TIA
Mike
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