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docu:csheet:net:firewall:syn_flooding

Protect your *nix server from SYN flooding


This are some basic anti-script-kiddie sysctl configurations to protect your server from SYN flooding

/etc/sysctl.conf
net.ipv4.conf.default.rp_filter=1
net.ipv4.conf.all.rp_filter=1
net.ipv4.tcp_syncookies=1
net.ipv4.tcp_max_syn_backlog=2048
net.ipv4.tcp_synack_retries=3


You can apply this changes live without rebooting using sysctl, for example:

sysctl net.ipv4.conf.default.rp_filter=1

Source: https://serverfault.com/questions/459607/tune-linux-kernel-against-syn-flood-attack

docu/csheet/net/firewall/syn_flooding.txt · Last modified: 2020/04/04 14:00 by admin