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--- sysctl:harden_the_system_using_sysctl [2017/04/04 14:55] – created peter
+++ sysctl:harden_the_system_using_sysctl [2019/12/04 21:46] (current) – removed peter
@@ Line 1: / Line 1: @@
-====== Sysctl - Harden the system using sysctl ======
-Edit /etc/sysctl.conf
-<file bash /etc/sysctl.conf>
-# Avoid a smurf attack
-net.ipv4.icmp_echo_ignore_broadcasts = 1
-# Turn on protection for bad icmp error messages
-net.ipv4.icmp_ignore_bogus_error_responses = 1
-# Turn on syncookies for SYN flood attack protection
-net.ipv4.tcp_syncookies = 1
-# Turn on and log spoofed, source routed, and redirect packets
-net.ipv4.conf.all.log_martians = 1
-net.ipv4.conf.default.log_martians = 1
-# No source routed packets here
-net.ipv4.conf.all.accept_source_route = 0
-net.ipv4.conf.default.accept_source_route = 0
-# Turn on reverse path filtering
-net.ipv4.conf.all.rp_filter = 1
-net.ipv4.conf.default.rp_filter = 1
-# Make sure no one can alter the routing tables
-net.ipv4.conf.all.accept_redirects = 0
-net.ipv4.conf.default.accept_redirects = 0
-net.ipv4.conf.all.secure_redirects = 0
-net.ipv4.conf.default.secure_redirects = 0
-# Don't act as a router
-net.ipv4.ip_forward = 0
-net.ipv4.conf.all.send_redirects = 0
-net.ipv4.conf.default.send_redirects = 0
-# Turn on execshild
-kernel.exec-shield = 1
-kernel.randomize_va_space = 1
-# Tuen IPv6
-net.ipv6.conf.default.router_solicitations = 0
-net.ipv6.conf.default.accept_ra_rtr_pref = 0
-net.ipv6.conf.default.accept_ra_pinfo = 0
-net.ipv6.conf.default.accept_ra_defrtr = 0
-net.ipv6.conf.default.autoconf = 0
-net.ipv6.conf.default.dad_transmits = 0
-net.ipv6.conf.default.max_addresses = 1
-# Optimization for port usefor LBs
-# Increase system file descriptor limit
-fs.file-max = 65535
-# Allow for more PIDs (to reduce rollover problems); may break some programs 32768
-kernel.pid_max = 65536
-# Increase system IP port limits
-net.ipv4.ip_local_port_range = 2000 65000
-# Increase TCP max buffer size setable using setsockopt()
-net.ipv4.tcp_rmem = 4096 87380 8388608
-net.ipv4.tcp_wmem = 4096 87380 8388608
-# Increase Linux auto tuning TCP buffer limits
-# min, default, and max number of bytes to use
-# set max to at least 4MB, or higher if you use very high BDP paths
-# Tcp Windows etc
-net.core.rmem_max = 8388608
-net.core.wmem_max = 8388608
-net.core.netdev_max_backlog = 5000
-net.ipv4.tcp_window_scaling = 1
-</file>