/etc/sysctl.conf
/proc/sys/


fs.file-max = 3145728
fs.file-max 对应 /proc/sys/fs/file-max

常见设置方法

echo value > /proc/sys/xx/yy
vi /etc/sysctl.conf 
sysctl -p   重新加载配置

sysctl -w kernel.domainname="example.com" 


禁止别人PING自己

echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all 
sysctl -w net.ipv4.icmp_echo_ignore_all=1


net.ipv4.ip_local_port_range = 10000  65535
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 30

net.ipv4.tcp_max_syn_backlog = 8192
# 同时保持TIME_WAIT的最大数量
net.ipv4.tcp_max_tw_buckets = 6000