Gist by paste.py @ 2015-04-10 23:26:17.734757

sysctl.conf

#
# /etc/sysctl.conf - Configuration file for setting system variables
# See /etc/sysctl.d/ for additonal system variables
# See sysctl.conf (5) for information.
#

#kernel.domainname = example.com

# Uncomment the following to stop low-level messages on console
#kernel.printk = 3 4 1 3

##############################################################3
# Functions previously found in netbase
#

# Uncomment the next two lines to enable Spoof protection (reverse-path filter)
# Turn on Source Address Verification in all interfaces to
# prevent some spoofing attacks
#net.ipv4.conf.default.rp_filter=1
#net.ipv4.conf.all.rp_filter=1

# Uncomment the next line to enable TCP/IP SYN cookies
# See http://lwn.net/Articles/277146/
# Note: This may impact IPv6 TCP sessions too
#net.ipv4.tcp_syncookies=1

# Uncomment the next line to enable packet forwarding for IPv4
net.ipv4.ip_forward=1

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host
net.ipv6.conf.all.forwarding=1


###################################################################
# Additional settings - these settings can improve the network
# security of the host and prevent against some network attacks
# including spoofing attacks and man in the middle attacks through
# redirection. Some network environments, however, require that these
# settings are disabled so review and enable them as needed.
#
# Do not accept ICMP redirects (prevent MITM attacks)
#net.ipv4.conf.all.accept_redirects = 0
#net.ipv6.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 accept IP source route packets (we are not a router)
#net.ipv4.conf.all.accept_source_route = 0
#net.ipv6.conf.all.accept_source_route = 0
#
# Log Martian Packets
#net.ipv4.conf.all.log_martians = 1
#

# Prefer empty disk cache instead of using swap.
vm.swappiness = 2
# Reserve 64M RAM for kernel
vm.min_free_kbytes = 65536
# Per socket read/write buffer size.
net.core.rmem_max = 8388608
net.core.wmem_max = 4194304
net.ipv4.tcp_rmem = 16384 262144 8388608
net.ipv4.tcp_wmem = 8192 131072 4194304
# Max global SYN_RECV connections
net.ipv4.tcp_max_syn_backlog = 16384
# Max queued packets for kernel handing
net.core.netdev_max_backlog = 4096
# Max per-socket SYN_RECV connections
net.core.somaxconn = 2048
# Max global TIME_WAIT connections.
net.ipv4.tcp_max_tw_buckets = 131072
# Refer to this article: https://en.wikipedia.org/wiki/TCP_congestion-avoidance_algorithm
net.ipv4.tcp_congestion_control = westwood

# Enlarge max pids
kernel.pid_max = 4194303
# Enlarge max connections, since there may be many connections from many clients.
net.ipv4.netfilter.ip_conntrack_max = 1048576
# TCP connection timed out after 2 hour of inactivity, which should be long enough for normal use.
net.ipv4.netfilter.ip_conntrack_tcp_timeout_established = 7200