SYN-Flood Addition
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Terri
MemberIn the "Harden the Secure Shell (SSH) & Create a Firewall" section there is an example iptables rule that can be used. I wanted to add some syn flood protection, but I'm not expert with iptables... Can anyone verify that this is valid.
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
:syn_flood - [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -j syn_flood
-A INPUT -p icmp -m limit --limit 1/sec --limit-burst 1 -j ACCEPT
-A INPUT -p icmp -j DROP
-A INPUT -i eth0 -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -i eth0 -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -i eth0 -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m limit --limit 3/hour -j LOG --log-prefix "iptables denied: " --log-level 7
-A OUTPUT -o lo -j ACCEPT
-A syn_flood -m limit --limit 1/sec --limit-burst 3 -j RETURN
-A syn_flood -j DROP
COMMITPosted 1 year ago # -
search the forums Terri .. adding an IPtables rule is outlined precisely in some thread or other.
Posted 1 year ago #
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