Linux Kernel /etc/sysctl.conf Hardening

Securing your Linux server is important to protect your data, intellectual property, and time, from the hands of crackers (hackers). The system administrator is responsible for security Linux box.

/etc/sysctl.conf file is used to configure kernel parameters at runtime.
Linux reads and applies settings from /etc/sysctl.conf at boot time.

Sample /etc/sysctl.conf:

# Turn on execshield
kernel.exec-shield=1
kernel.randomize_va_space=1
# Enable IP spoofing protection
net.ipv4.conf.all.rp_filter=1
# Disable IP source routing
net.ipv4.conf.all.accept_source_route=0
# Ignoring broadcasts request
net.ipv4.icmp_echo_ignore_broadcasts=1
net.ipv4.icmp_ignore_bogus_error_messages=1
# Make sure spoofed packets get logged
net.ipv4.conf.all.log_martians = 1