Bridge Firewall Linux

Bridge Firewall Linux

I'm use this install on debian etch. 

# apt-get install bridge-utils
# brctl addbr br0
# brctl addif br0 eth0
# brctl addif br0 eth1
# brctl stp br0 on
# ifconfig eth0 0.0.0.0 up
# ifconfig eth1 0.0.0.0 up
# ifconfig br0 1.1.1.1 netmask 255.0.0.0 up
# route add default gw 1.1.1.1

 Put all above config in /etc/rc.local

 Install vuurmuur iptables gui for Debian&Ubuntu. Or manual iptables

 This is an example of the basic rules that could be used for either of these setups.

 iptables -F FORWARD
 iptables -P FORWARD DROP
 iptables -A FORWARD -s 0.0.0.0/0.0.0.0 -d 0.0.0.0/0.0.0.0 -m state --state INVALID -j DROP
 iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
 
 # Some funny rules but not in a classic Iptables sorry ...
 # Limit ICMP 
 # iptables -A FORWARD -p icmp -m limit --limit 4/s -j ACCEPT
 # Match string, a good simple method to block some VIRUS very quickly
 # iptables -I FORWARD -j DROP -p tcp -s 0.0.0.0/0 -m string --string "cmd.exe"
 
 # Block all MySQL connection just to be sure
 iptables -A FORWARD -p tcp -s 0/0 -d 62.3.3.0/24 --dport 3306 -j DROP
 
 # Linux Mail Server Rules
 
 # Allow FTP-DATA (20), FTP (21), SSH (22) 
 iptables -A FORWARD -p tcp -s 0.0.0.0/0 -d 62.3.3.27/32 --dport 20:22 -j ACCEPT
 
 # Allow the Mail Server to connect to the outside
 # Note: This is *not* needed for the previous connections 
 # (remember: stateful filtering) and could be removed.
 iptables -A FORWARD -p tcp -s 62.3.3.27/32 -d 0/0 -j ACCEPT
 
 # WWW Server Rules
 
 # Allow HTTP ( 80 ) connections with the WWW server
 iptables -A FORWARD -p tcp -s 0.0.0.0/0 -d 62.3.3.28/32 --dport 80 -j ACCEPT
 
 # Allow HTTPS ( 443 ) connections with the WWW server
 iptables -A FORWARD -p tcp -s 0.0.0.0/0 -d 62.3.3.28/32 --dport 443 -j ACCEPT
 
 # Allow the WWW server to go out
 # Note: This is *not* needed for the previous connections 
 # (remember: stateful filtering) and could be removed.
 iptables -A FORWARD -p tcp -s 62.3.3.28/32 -d 0/0 -j ACCEPT