CentOS 7 内核优化

 

[root@DaMoWang ~]# vim /etc/sysctl.conf
#关闭ipv6
net.ipv6.conf.all.disable_ipv6 =
net.ipv6.conf.default.disable_ipv6 = 

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

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

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

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

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

#关闭sysrq功能
kernel.sysrq = 

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

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

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

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

#timewait的数量，默认180000
net.ipv4.tcp_max_tw_buckets =
net.ipv4.tcp_sack =
net.ipv4.tcp_window_scaling =
net.ipv4.tcp_rmem =
net.ipv4.tcp_wmem =
net.core.wmem_default =
net.core.rmem_default =
net.core.rmem_max =
net.core.wmem_max = 

#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 = 

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

#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 =
net.ipv4.tcp_timestamps = 

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

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

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

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

#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 = 

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

#修改防火墙表大小，默认65536
#net.netfilter.nf_conntrack_max=
#net.netfilter.nf_conntrack_tcp_timeout_established=

# 确保无人能修改路由表
net.ipv4.conf.all.accept_redirects =
net.ipv4.conf.default.accept_redirects =
net.ipv4.conf.all.secure_redirects =
net.ipv4.conf.default.secure_redirects = 

使其生效

[root@DaMoWang ~]# sysctl -p
sysctl: /etc/sysctl.conf(): invalid syntax, continuing...
net.ipv6.conf.all.disable_ipv6 =
net.ipv6.conf.default.disable_ipv6 =
net.ipv4.icmp_echo_ignore_broadcasts =
net.ipv4.icmp_ignore_bogus_error_responses =
net.ipv4.ip_forward =
net.ipv4.conf.all.send_redirects =
net.ipv4.conf.default.send_redirects =
net.ipv4.conf.all.rp_filter =
net.ipv4.conf.default.rp_filter =
net.ipv4.conf.all.accept_source_route =
net.ipv4.conf.default.accept_source_route =
kernel.sysrq =
kernel.core_uses_pid =
net.ipv4.tcp_syncookies =
kernel.msgmnb =
kernel.msgmax =
kernel.shmmax =
kernel.shmall =
net.ipv4.tcp_max_tw_buckets =
net.ipv4.tcp_sack =
net.ipv4.tcp_window_scaling =
net.ipv4.tcp_rmem =
net.ipv4.tcp_wmem =
net.core.wmem_default =
net.core.rmem_default =
net.core.rmem_max =
net.core.wmem_max =
net.core.netdev_max_backlog =
net.ipv4.tcp_max_orphans =
net.ipv4.tcp_max_syn_backlog =
net.ipv4.tcp_timestamps =
net.ipv4.tcp_synack_retries =
net.ipv4.tcp_syn_retries =
net.ipv4.tcp_tw_recycle =
net.ipv4.tcp_tw_reuse =
net.ipv4.tcp_mem =
net.ipv4.tcp_fin_timeout =
net.ipv4.tcp_keepalive_time =
net.ipv4.ip_local_port_range =
net.ipv4.conf.all.accept_redirects =
net.ipv4.conf.default.accept_redirects =
net.ipv4.conf.all.secure_redirects =
net.ipv4.conf.default.secure_redirects =