sudo vi /etc/sysctl.conf

# Kernel sysctl configuration file for Red Hat Linux## For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and# sysctl.conf(5) for more details.# Controls the System Request debugging functionality of the kernelkernel.sysrq = 1# Controls whether core dumps will append the PID to the core filename# Useful for debugging multi-threaded applicationskernel.core_uses_pid = 1# Controls the maximum size of a message, in byteskernel.msgmnb = 65536# Controls the default maxmimum size of a mesage queuekernel.msgmax = 65536# Controls the maximum shared segment size, in byteskernel.shmmax = 68719476736# Controls the maximum number of shared memory segments, in pageskernel.shmall = 4294967296# Controls IP packet forwardingnet.ipv4.ip_forward = 0# Controls source route verificationnet.ipv4.conf.default.rp_filter = 1# Do not accept source routingnet.ipv4.conf.default.accept_source_route = 0# Controls the use of TCP syncookiesnet.ipv4.tcp_syncookies = 1net.core.somaxconn = 10240net.ipv4.tcp_tw_reuse = 1net.ipv4.tcp_tw_recycle = 1net.ipv4.tcp_fin_timeout = 30net.ipv4.tcp_keepalive_time = 300net.ipv4.tcp_synack_retries = 3net.ipv4.tcp_syn_retries = 3net.core.rmem_max = 16777216net.core.wmem_max = 16777216net.ipv4.tcp_rmem = 4096 87380 16777216net.ipv4.tcp_wmem = 4096 65536 16777216net.ipv4.tcp_no_metrics_save = 0net.core.netdev_max_backlog = 2500net.ipv4.tcp_max_syn_backlog = 4196net.ipv6.conf.all.disable_ipv6 = 1net.ipv6.conf.default.disable_ipv6 = 1                  xen.independent_wallclock = 1

sudo sysctl -p