dns

#----------
    # PING
    #----------
    iptables -A INPUT -p icmp --icmp-type 8 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
    iptables -A OUTPUT -p icmp --icmp-type 8 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT

    #----------
    # DNS
    #----------
    # UDP
    iptables -A INPUT -i eth0 -p udp --sport 53 -m state --state ESTABLISHED -j ACCEPT
    iptables -A OUTPUT -o eth0 -p udp --dport 53 -m state --state NEW,ESTABLISHED -j ACCEPT
    # TCP
    iptables -A INPUT -i eth0 -p tcp --sport 53 -m state --state ESTABLISHED -j ACCEPT
    iptables -A OUTPUT -o eth0 -p tcp --dport 53 -m state --state NEW,ESTABLISHED -j ACCEPT