打开/etc/sysctl.conf文件，添加如下信息：
 
 net.ipv4.tcp_retries2 = 5
 net.ipv4.tcp_fin_timeout = 30
 net.ipv4.tcp_keepalive_time = 1200
 net.ipv4.tcp_keepalive_intvl = 30
 net.ipv4.tcp_keepalive_probes = 3
 net.ipv4.tcp_syncookies = 1
 net.ipv4.tcp_tw_reuse = 1
 net.ipv4.tcp_tw_recycle = 1
 net.ipv4.ip_local_port_range = 1024 65000
 net.ipv4.tcp_max_syn_backlog = 8192
 #net.ipv4.tcp_max_tw_buckets = 5000
        使用/sbin/sysctl -p 命令，是修改的信息立即生效