Common iptables applications (1)

IptablesVery good and powerful. All the friends who have used it say yes. Well, this article introduces some common applications!

1. ICMP-related applications

Make yourself unable to ping 127.0.0.1

Iptables-a input-s 127.0.0.1-p icmp-j DROP

The IP address range of 192.168.0.0/24 cannot be pinged to the local machine.

Iptables-a input-s 192.168.0.0/24-p icmp-j DROP

Ii. Disable all machines

# Iptables-a input-s 0/0-p icmp-j DROP

# ICMP (PING) accept! Echo-request

/Sbin/iptables-a input-p icmp -- icmp-type! Echo-request-j ACCEPT

Accept_redirects

# Echo "0">/proc/sys/net/ipv4/conf/all/accept_redirects

Or

# Sysctl net. ipv4.conf. all. accept_redirects = "0"

3. Prohibit IP Access to yourself

[Root @ linux root] # iptables-a input-s 192.168.0.253-j DROP

Iv. Blocking MSN

/Sbin/iptables-I FORWARD-d gateway.messenger.hotmail.com-j DROP

/Sbin/iptables-I FORWARD-p tcp -- dport 1863-j DROP

5. Blocking QQ

/Sbin/iptables-a forward-p tcp-d tcpconn.tencent.com -- dport 80-j DROP

/Sbin/iptables-a forward-p tcp-d tcpconn.tencent.com -- dport 443-j DROP

/Sbin/iptables-a forward-p tcp-d tcpconn2.tencent.com-j DROP

/Sbin/iptables-a forward-I eth0-p udp -- dport 8000-j DROP