Requerimientos
- iptables
- packet filter
#!/bin/bash
#=====================
# Habilitamos ip forward
#---------------------
echo 1 > /proc/sys/net/ipv4/ip_forward
#=====================
# hacemos un flush
#---------------------
/sbin/iptables -F
/sbin/iptables -t nat -F
#=====================
# empezamos el bloqueo
#---------------------
/sbin/iptables -t filter -A INPUT -p TCP -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -t filter -A INPUT -p UDP -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -t filter -A INPUT -p ICMP -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -t filter -A INPUT -m state --state INVALID -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j LOG --log-prefix "FIN: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,PSH PSH -j LOG --log-prefix "PSH: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,PSH PSH -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,URG URG -j LOG --log-prefix "URG: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ACK,URG URG -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL ALL -j LOG --log-prefix "XMAS scan: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL ALL -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL NONE -j LOG --log-prefix "NULL scan: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL NONE -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j LOG --log-prefix "pscan: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j LOG --log-prefix "pscan 2: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j LOG --log-prefix "pscan 2: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL SYN,FIN -j LOG --log-prefix "SYNFIN-SCAN: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL SYN,FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL URG,PSH,FIN -j LOG --log-prefix "NMAP-XMAS-SCAN: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL URG,PSH,FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL FIN -j LOG --log-prefix "FIN-SCAN: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL URG,PSH,SYN,FIN -j LOG --log-prefix "NMAP-ID: "
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags ALL URG,PSH,SYN,FIN -j DROP
/sbin/iptables -t filter -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j LOG --log-prefix "SYN-RST: "