修改配置文件

# vim /etc/sysctl.conf

# 写入以下内容

# 关闭ipv6

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

# 避免放大攻击
net.ipv4.icmp_echo_ignore_broadcasts = 1

# 开启恶意icmp错误消息保护
net.ipv4.icmp_ignore_bogus_error_responses = 1

# 关闭路由转发
net.ipv4.ip_forward = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0

# 开启反向路径过滤
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# 处理无源路由的包
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# 关闭sysrq功能
kernel.sysrq = 0

# core文件名中添加pid作为扩展名
kernel.core_uses_pid = 1

# 开启SYN洪水攻击保护
net.ipv4.tcp_syncookies = 1

# 修改消息队列长度
kernel.msgmnb = 65536
kernel.msgmax = 65536

# 设置最大内存共享段大小bytes
kernel.shmmax = 68719476736
kernel.shmall = 4294967296

# timewait的数量，默认180000

net.ipv4.tcp_max_tw_buckets = 6000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096        87380   4194304
net.ipv4.tcp_wmem = 4096        16384   4194304
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216

# 每个网络接口接收数据包的速率比内核处理这些包的速率快时，允许送到队列的数据包的最大数目
net.core.netdev_max_backlog = 262144

# 限制仅仅是为了防止简单的DoS 攻击
net.ipv4.tcp_max_orphans = 3276800

# 未收到客户端确认信息的连接请求的最大值
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0

# 内核放弃建立连接之前发送SYNACK 包的数量
net.ipv4.tcp_synack_retries = 1

# 内核放弃建立连接之前发送SYN 包的数量
net.ipv4.tcp_syn_retries = 1

# 启用timewait 快速回收
net.ipv4.tcp_tw_recycle = 1

# 开启重用。允许将TIME-WAIT sockets 重新用于新的TCP 连接
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 1

# 当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2 小时
net.ipv4.tcp_keepalive_time = 30

# 允许系统打开的端口范围
net.ipv4.ip_local_port_range = 1024    65000

# 修改防火墙表大小，默认65536

# net.netfilter.nf_conntrack_max=655350

# net.netfilter.nf_conntrack_tcp_timeout_established=1200

# 确保无人能修改路由表
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
vm.max_map_count = 655360
fs.file-max=655350

使配置文件生效

# sysctl -p

limits.conf 配置

# vim /etc/security/limits.conf

# 在末尾添加以下内容，保存后，重启服务器即可生效

root soft nofile 65535
root hard nofile 65535
* soft nofile 65535
* hard nofile 65535