linux tips

• 允许 IP 转发

  # To enable IP packet forwarding please edit /etc/sysctl.conf with your editor of choice and set:
  
  # Controls IP packet forwarding
  net.ipv4.ip_forward = 1
  
  
  # You can then verify your settings with:
  /sbin/sysctl -p

• 创建虚拟 IP 地址

  cp /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-ens33:0
  
  # 删除
  ONBOOT=YES
  
  # 添加
  ONPARENT=YES
  
  # 目的：父接口启动时才启动。
  # ONBOOT=YES 会把父接口启动

• 单网卡多Ip

  TYPE=Ethernet
  PROXY_METHOD=none
  BROWSER_ONLY=no
  BOOTPROTO=static
  DEFROUTE=yes
  IPV4_FAILURE_FATAL=no
  IPV6INIT=no
  IPV6_AUTOCONF=yes
  IPV6_DEFROUTE=yes
  IPV6_FAILURE_FATAL=no
  IPV6_ADDR_GEN_MODE=stable-privacy
  NAME=ens32
  UUID=0d6815b3-b400-47cf-a418-df8c914568a0
  DEVICE=ens32
  ONBOOT=yes
  IPADDR0=192.168.10.130
  NETMASK0=255.255.255.0
  GATEWAY0=192.168.10.1
  IPADDR1=172.20.10.3
  NETMASK1=255.255.255.240
  GATEWAY1=172.20.10.1

  ip地址设置

  ip addr add 172.20.10.5/28 dev enp0s3

  默认路由添加

  ip route add default via 172.20.10.1

• 关闭ipv6
  为内核加载添加选项“ipv6.disable=1”

  vi /etc/default/grub
  grub2-mkconfig -o /boot/grub2/grub.cfg

  
  模块加载级别关闭ipv6

  vi /etc/sysctl.conf
  net.ipv6.conf.all.disable_ipv6 = 1
  net.ipv6.conf.default.disable_ipv6 = 1
  sysctl -p

  运行时关闭 IPv6

  echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6
  echo 1 > /proc/sys/net/ipv6/conf/default/disable_ipv6

  sysctl -w net.ipv6.conf.all.disable_ipv6=1
  sysctl -w net.ipv6.conf.default.disable_ipv6=1

• 修改运行级别

  systemctl set-default multi-user
  systemctl get-default

• 修改时区

  cat /etc/timezone
  timedatectl list-timezones
  timedatectl list-timezones | grep -i shanghai
  timedatectl set-timezone Asia/Shanghai

  时间同步

  timedatectl set-ntp true

CentOS