mirror of
https://github.com/ChrisTitusTech/firewallsetup.git
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68 lines
2.5 KiB
Bash
68 lines
2.5 KiB
Bash
#!/bin/bash
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#
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# iptables example configuration script
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# Drop ICMP echo-request messages sent to broadcast or multicast addresses
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echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
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# Drop source routed packets
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echo 0 > /proc/sys/net/ipv4/conf/all/accept_source_route
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# Enable TCP SYN cookie protection from SYN floods
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echo 1 > /proc/sys/net/ipv4/tcp_syncookies
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# Don't accept ICMP redirect messages
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echo 0 > /proc/sys/net/ipv4/conf/all/accept_redirects
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# Don't send ICMP redirect messages
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echo 0 > /proc/sys/net/ipv4/conf/all/send_redirects
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# Enable source address spoofing protection
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echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
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# Log packets with impossible source addresses
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echo 1 > /proc/sys/net/ipv4/conf/all/log_martians
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# Flush all chains
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/sbin/iptables --flush
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# Allow unlimited traffic on the loopback interface
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/sbin/iptables -A INPUT -i lo -j ACCEPT
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/sbin/iptables -A OUTPUT -o lo -j ACCEPT
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# Set default policies
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/sbin/iptables --policy INPUT DROP
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/sbin/iptables --policy OUTPUT DROP
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/sbin/iptables --policy FORWARD DROP
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# Previously initiated and accepted exchanges bypass rule checking
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# Allow unlimited outbound traffic
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/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
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/sbin/iptables -A OUTPUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
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#Ratelimit SSH for attack protection
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/sbin/iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --update --seconds 60 --hitcount 4 -j DROP
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/sbin/iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --set
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/sbin/iptables -A INPUT -p tcp --dport 22 -m state --state NEW -j ACCEPT
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# Allow certain ports to be accessible from the outside
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/sbin/iptables -A INPUT -p tcp --dport 25565 -m state --state NEW -j ACCEPT #Minecraft
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/sbin/iptables -A INPUT -p tcp --dport 8123 -m state --state NEW -j ACCEPT #Dynmap plugin
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# Other rules for future use if needed. Uncomment to activate
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# /sbin/iptables -A INPUT -p tcp --dport 80 -m state --state NEW -j ACCEPT # http
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# /sbin/iptables -A INPUT -p tcp --dport 443 -m state --state NEW -j ACCEPT # https
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# UDP packet rule. This is just a random udp packet rule as an example only
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# /sbin/iptables -A INPUT -p udp --dport 5021 -m state --state NEW -j ACCEPT
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# Allow pinging of your server
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/sbin/iptables -A INPUT -p icmp --icmp-type 8 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
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# Drop all other traffic
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/sbin/iptables -A INPUT -j DROP
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# print the activated rules to the console when script is completed
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/sbin/iptables -nL
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