# Add these lines to the end of /etc/rc.d/rc.local ##### Begin DoS Prevention ##### # shut some DoS stuff down echo 1 > /proc/sys/net/ipv4/tcp_syncookies echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts # increase the local port range echo 1024 65535 > /proc/sys/net/ipv4/ip_local_port_range # increase the SYN backlog queue echo 2048 > /proc/sys/net/ipv4/tcp_max_syn_backlog echo 0 > /proc/sys/net/ipv4/tcp_sack echo 0 > /proc/sys/net/ipv4/tcp_timestamps echo 64000 > /proc/sys/fs/file-max ulimit -n 64000 # stop source routing for i in /proc/sys/net/ipv4/conf/*/accept_source_route do echo 0 > $i done # enable reverse-path filtering for i in /proc/sys/net/ipv4/conf/*/rp_filter do echo 1 > $i done ##### End DoS Prevention #####