?????Щ????? Linux iptables ??????????????????????????
????iptables-network-security
????# 1. ??????????й???
????iptables -F
????# 2. ???????? chain ????
????iptables -P INPUT DROP
????iptables -P FORWARD DROP
????iptables -P OUTPUT DROP
????# 3. ??????????? IP ???
????#BLOCK_THIS_IP="x.x.x.x"
????#iptables -A INPUT -s "$BLOCK_THIS_IP" -j DROP
????# 4. ??????????????incoming??SSH
????iptables -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW??ESTABLISHED -j ACCEPT
????iptables -A OUTPUT -o eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
????# 5. ???????????????????? SSH
????#iptables -A INPUT -i eth0 -p tcp -s 192.168.200.0/24 --dport 22 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
????# 6. ??????????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
????# 7. ???????????????? SSH??HTTP ?? HTTPS??
????iptables -A INPUT -i eth0 -p tcp -m multiport --dports 22??80??443 -m state --state NEW??ESTABLISHED -j ACCEPT
????iptables -A OUTPUT -o eth0 -p tcp -m multiport --sports 22??80??443 -m state --state ESTABLISHED -j ACCEPT
????# 8. ?????????outgoing??SSH
????iptables -A OUTPUT -o eth0 -p tcp --dport 22 -m state --state NEW??ESTABLISHED -j ACCEPT
????iptables -A INPUT -i eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
????# 9. ??????????outgoing??SSH??????????????????????
????#iptables -A OUTPUT -o eth0 -p tcp -d 192.168.101.0/24 --dport 22 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A INPUT -i eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
????# 10. ??????????outgoing?? HTTPS
????iptables -A OUTPUT -o eth0 -p tcp --dport 443 -m state --state NEW??ESTABLISHED -j ACCEPT
????iptables -A INPUT -i eth0 -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT
????# 11. ??????? HTTPS ?????????????
????#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 0 -j DNAT --to-destination 192.168.1.101:443
????#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 1 -j DNAT --to-destination 192.168.1.102:443
????#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 2 -j DNAT --to-destination 192.168.1.103:443
????# 12. ????????? Ping
????iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
????iptables -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT
????# 13. ????????? Ping
????iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
????iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT
????# 14. ????????loopback??????
????iptables -A INPUT -i lo -j ACCEPT
????iptables -A OUTPUT -o lo -j ACCEPT
????# 15. ???? packets ??????????????
????# if eth1 is connected to external network (internet)
????# if eth0 is connected to internal network (192.168.1.x)
????iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT
????# 16. ?????????  DNS
????iptables -A OUTPUT -p udp -o eth0 --dport 53 -j ACCEPT
????iptables -A INPUT -p udp -i eth0 --sport 53 -j ACCEPT
????# 17. ???? NIS ????
????# rpcinfo -p | grep ypbind ; This port is 853 and 850
????#iptables -A INPUT -p tcp --dport 111 -j ACCEPT
????#iptables -A INPUT -p udp --dport 111 -j ACCEPT
????#iptables -A INPUT -p tcp --dport 853 -j ACCEPT
????#iptables -A INPUT -p udp --dport 853 -j ACCEPT
????#iptables -A INPUT -p tcp --dport 850 -j ACCEPT
????#iptables -A INPUT -p udp --dport 850 -j ACCEPT
????# 18. ?????????????? rsync ??????
????#iptables -A INPUT -i eth0 -p tcp -s 192.168.101.0/24 --dport 873 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 873 -m state --state ESTABLISHED -j ACCEPT
????# 19. ????????????????????? MySQL ??????
????#iptables -A INPUT -i eth0 -p tcp -s 192.168.200.0/24 --dport 3306 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 3306 -m state --state ESTABLISHED -j ACCEPT
????# 20. ???? Sendmail ?? Postfix
????iptables -A INPUT -i eth0 -p tcp --dport 25 -m state --state NEW??ESTABLISHED -j ACCEPT
????iptables -A OUTPUT -o eth0 -p tcp --sport 25 -m state --state ESTABLISHED -j ACCEPT
????# 21. ???? IMAP ?? IMAPS
????#iptables -A INPUT -i eth0 -p tcp --dport 143 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 143 -m state --state ESTABLISHED -j ACCEPT
????#iptables -A INPUT -i eth0 -p tcp --dport 993 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 993 -m state --state ESTABLISHED -j ACCEPT
????# 22. ???? POP3 ?? POP3S
????#iptables -A INPUT -i eth0 -p tcp --dport 110 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 110 -m state --state ESTABLISHED -j ACCEPT
????#iptables -A INPUT -i eth0 -p tcp --dport 995 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 995 -m state --state ESTABLISHED -j ACCEPT
????# 23. ??? DoS ????
????iptables -A INPUT -p tcp --dport 80 -m limit --limit 25/minute --limit-burst 100 -j ACCEPT
????# 24. ???? 422 ???????? 22 ???
????#iptables -t nat -A PREROUTING -p tcp -d 192.168.102.37 --dport 422 -j DNAT --to 192.168.102.37:22
????#iptables -A INPUT -i eth0 -p tcp --dport 422 -m state --state NEW??ESTABLISHED -j ACCEPT
????#iptables -A OUTPUT -o eth0 -p tcp --sport 422 -m state --state ESTABLISHED -j ACCEPT
????# 25. ???????????????Log??
????iptables -N LOGGING
????iptables -A INPUT -j LOGGING
????iptables -A LOGGING -m limit --limit 2/min -j LOG --log-prefix "IPTables Packet Dropped: " --log-level 7
????iptables -A LOGGING -j DROP