If this is the wrong list, please tell me where i should post this. Here is my iptables setup.
As you can see I want a very secure firewall (and gateway) but i do want to have the ability to ssh from the outside and i am still not sure how to go about it. Anyway, here is my setup and i would appreciate it if any security gurus would comment on it. Thanks -------------------------------------------- #!/bin/sh #chmod 755 is needed to make this executable #Turn on ip_forward with this command echo 1 > /proc/sys/net/ipv4/ip_forward #Clean up tables iptables -F iptables -X iptables -Z #This allow maquerading iptables -t nat -A POSTROUTING -j MASQUERADE #This allow a connection to the gateway from inside the network #tank iptables -A INPUT -s 192.168.2.2 -j ACCEPT iptables -A OUTPUT -d 192.168.2.2 -j ACCEPT #evvie iptables -A INPUT -s 192.168.2.20 -j ACCEPT iptables -A OUTPUT -d 192.168.2.20 -j ACCEPT #text iptables -A INPUT -s 192.168.2.3 -j ACCEPT iptables -A OUTPUT -d 192.168.2.3 -j ACCEPT # Disallow NEW and INVALID incoming or forwarded packets from eth0. #iptables -A INPUT -i eth0 -m state --state NEW,INVALID -j DROP #iptables -A FORWARD -i eth0 -m state --state NEW,INVALID -j DROP #Most people just have a single PPP connection to the Internet, #and don't want anyone coming back into their network, or the firewall: ## Create chain which blocks new connections, except if coming from inside. #I have an eth0 so i made tha appropriate changes iptables -N block iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A block -m state --state NEW -i ! eth0 -j ACCEPT iptables -A block -j DROP ## Jump to that chain from INPUT and FORWARD chains. iptables -A INPUT -j block iptables -A FORWARD -j block
