I finally added a firewall to debian and used iptables.

Finally, we added a firewall to debian and used iptables-the Linux Release Technology-Debian information. The following is a detailed description. Author: lpfrx

Write the following command in the firewall. sh file:

# Vim/etc/firewall. sh

Iptables-F
Iptables-N FIREWALL
Iptables-F FIREWALL
Iptables-a input-j FIREWALL
Iptables-a forward-j FIREWALL
Iptables-a firewall-p tcp-m tcp? Dport 110? Syn-j ACCEPT
Iptables-a firewall-p tcp-m tcp? Dport 80? Syn-j ACCEPT

# Webmin
Iptables-a firewall-p tcp-m tcp? Dport 10000? Syn-j ACCEPT

Iptables-a firewall-p tcp-m tcp? Dport 22? Syn-j ACCEPT
Iptables-a firewall-I lo-j ACCEPT
Iptables-a firewall-p udp-m udp? Sport 53-j ACCEPT

Iptables-a firewall-p tcp-m tcp? Syn-j REJECT
Iptables-a firewall-p udp-m udp-j REJECT

Then:
# Chmod 755/etc/firewall. sh

Continue, add firewall. sh to startup:
# Echo sh/etc/firewall. sh>/etc/init. d/rc. local

In this way, Debian adds a fire wall, which is easy to do. It is easy to use iptables to build a fire wall in Linux. Of course, it is simple. The complexity should be carefully studied.

Clear command: iptables-F
View command: iptables-L