I want to block all subnets outside the US. I've made a script that has all of the US subnets in it. I want to disallow or DROP all but my list. Can someone give me an example of how I can start by denying everything?
This is the output from -L
Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT tcp -- anywhere anywhere tcp dpt:ftp state NEW DROP icmp -- anywhere anywhere Chain FORWARD (policy DROP) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
And these are the rules
iptables --F iptables --policy INPUT DROP iptables --policy FORWARD DROP iptables --policy OUTPUT ACCEPT iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A INPUT -p tcp -i eth0 --dport 21 -m state --state NEW -j ACCEPT iptables -A INPUT -p icmp -j DROP
Just for clarity, with these rules, I can still connect to port 21 without my subnet list. I want to block ALL subnets and just open those inside the US.