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Re: Debian and IP Chains?



>doing some firewalling.  I'm running 2.1.104 on my gateway, and I've played
>with ipfwcahins some.  

ipchains :)

>2) Can someone share a recipe to allow incoming/outgoing ssh traffic.  I

First, you have to allow traffic into the firewall:

# Any packets coming from your internal network is good
ipchains -A input -i eth0 -j ACCEPT
# next allow ssh port 22 through the ppp0 port
ipchains -A input -d <external-ip-of-firewall> 22 -j ACCEPT

That's it.  You put both commands in your ppp-up script.  I did this
successfully.  In the ppp-in script there is a macro name for the ip
address of the ppp0 port, and you put that variable ($ipaddr ???) in place
of the <external-ip-of-firewall> and you are in good shape.

Then, in your ppp-down batch file, you put one command:
# kill the PPP0 port from a firewall standpoint
ipchains -A input -i ppp0 -j DENY

This ensures when you re-connect to the internet, or dial up server, the
firewall commands have been cleared and not duplicated.  Otherwise if you
dial up, lose connect, and repeat 20 times (lousy ISP <G>), you end up with
a giant firewall table that doesn't do much.  Just slows Linux down
unnecessarily.

Hope that helps.  I'm slowly learning, and got this far :)  I'm working on
port forwarding next.


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

Wanted - RWD Buick Flywheel that fits the 3.8L / 4.1L!
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