Centos IPTables configuration for external firewall
- by user137974
Current setup
Centos which is a Web, Mail (Postfix,Dovecot), FTP Server and Gateway with public ip and private ip (for LAN Gateway).
We are planning to implement external firewall box and bring the server to LAN
Please guide on configuring IPTables... Unable to receive mail and outgoing mail stays in postfix queue and is sent after delaying...
The local ip of the server is 192.168.1.220
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP
incoming HTTP
iptables -A INPUT -i eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT
outgoing HTTP
iptables -A OUTPUT -o eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
FTP
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d 192.168.1.220 --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s 192.168.1.220 --sport 21 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d 192.168.1.220 --dport 1024:65535 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -p tcp -s 192.168.1.220 --sport 1024:65535 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
SMTP
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d 192.168.1.220 --dport 25 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s 192.168.1.220 --sport 25 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s 192.168.1.220 --sport 1024:65535 -d 0/0 --dport 25 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s 0/0 --sport 25 -d 192.168.1.220 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
POP3
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d 192.168.1.220 --dport 110 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s 192.168.1.220 --sport 110 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
