# /etc/sysctl.conf - Configuration file for setting system variables
# See sysctl.conf (5) for information. Also see the files under
# Documentation/sysctl/, Documentation/filesystems/proc.txt, and
# Documentation/networking/ip-sysctl.txt in the kernel sources 
# (/usr/src/kernel-$version if you have a kernel-package installed)
# for more information of the values that can be defined here.

#
# Be warned that /etc/init.d/procps is executed to set the following
# variables.  However, after that, /etc/init.d/networking sets some
# network options with builtin values.  These values may be overridden
# using /etc/network/options.
#
#kernel.domainname = example.com

# Additional settings - adapted from the script contributed
# by Dariusz Puchala (see below)
# Ignore ICMP broadcasts
net/ipv4/icmp_echo_ignore_broadcasts = 1
#
# Ignore bogus ICMP errors
net/ipv4/icmp_ignore_bogus_error_responses = 1
# 
# Do not accept ICMP redirects (prevent MITM attacks)
net/ipv4/conf/all/accept_redirects = 0
# _or_
# Accept ICMP redirects only for gateways listed in our default
# gateway list (enabled by default)
# net/ipv4/conf/all/secure_redirects = 1
#
# Do not send ICMP redirects (we are not a router)
net/ipv4/conf/all/send_redirects = 0
#
# Do not forward IP packets (we are not a router)
# Note: Make sure that /etc/network/options has 'ip_forward=no'
net/ipv4/conf/all/forwarding = 0
#
# Enable TCP Syn Cookies
# Note: Make sure that /etc/network/options has 'syncookies=yes'
net/ipv4/tcp_syncookies = 1
#
# Log Martian Packets
net/ipv4/conf/all/log_martians = 1
#
# Turn on Source Address Verification in all interfaces to
# prevent some spoofing attacks
# Note: Make sure that /etc/network/options has 'spoofprotect=yes'
net/ipv4/conf/all/rp_filter = 1
#
# Do not accept IP source route packets (we are not a router)
net/ipv4/conf/all/accept_source_route = 0