Only allow outbound connections

CrEsPo · 01-01-2007, 12:17 AM

I want to block all incoming and forwarding connections, except those necessary for everyday use. I had tried that, but it I lose connection to the internet, so obviously there are some exceptions, what are they? I thought just blocking them would be enough, but I need some exceptions

.

In summary, I'm looking for exceptions that will allow me to connect to the internet with minimal exceptions used. If it helps, the laptop uses DHCP and uses a network printer. That's pretty much the only things I would see being needed. Any help is greatly appreciated.

bosewicht · 01-01-2007, 01:08 AM

Have you looked into iptables? how are you trying to limit connectivity?

CrEsPo · 01-01-2007, 01:28 AM

Sorry, that was what I meant. I want to do this using iptables. I tried using "iptables -P INPUT DROP" and "iptables -P FORWRAD DROP", but I lost connectivity to the internet, so obviously their are some exceptions which I'm not sure of.

win32sux · 01-01-2007, 02:37 AM

Quote:

Originally Posted by CrEsPo

Sorry, that was what I meant. I want to do this using iptables. I tried using "iptables -P INPUT DROP" and "iptables -P FORWRAD DROP", but I lost connectivity to the internet, so obviously their are some exceptions which I'm not sure of.

well, the FORWARD rule is unrelated if you're not doing forwarding - and it doesn't sound like you are... but check with a:

Code:

cat /proc/sys/net/ipv4/ip_forward

as for the "iptables -P INPUT DROP", you are correct in that you'd need a couple rules in order for that to work... they are:

Code:

iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT

just my

...

CrEsPo · 01-01-2007, 11:54 AM

Thank-you, worked like a charm and it's exactly what I needed

. Thanks again

.