in this file i ghave only this configurate.
# /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 = 4 4 1 7
kernel.shmmax= 2147483648
##############################################################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
# this disables tcp window scaling (
),
# and is not recommended.
#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
#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.
#
# 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
#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
#
# the contents of /proc/<pid>/maps and smaps files are only visible to
# readers that are allowed to ptrace() the process
# kernel.maps_protect = 1