前言生产环境中，Public IP 经常比较有限，Linux GateWay可以充分利用有限IP为更多的机器提供网络服务，也可以有意识地将某些服务器隐藏在后面，即可以主动获取网络资源，又避免被动访问，更加安全

概要开启内核转发调整内核参数 net.ipv4.ip_forward 开启转发

代码语言：javascript复制[root@linux-gateway ~]# grep forward /etc/sysctl.conf

# Controls IP packet forwarding

net.ipv4.ip_forward = 1

[root@linux-gateway ~]# sysctl -p 使其生效，然后使用 sysctl -a 来进行确认

代码语言：javascript复制[root@linux-gateway ~]# sysctl -a | grep forwarding

net.ipv4.conf.all.forwarding = 1

net.ipv4.conf.all.mc_forwarding = 0

net.ipv4.conf.default.forwarding = 1

net.ipv4.conf.default.mc_forwarding = 0

net.ipv4.conf.lo.forwarding = 1

net.ipv4.conf.lo.mc_forwarding = 0

net.ipv4.conf.em4.forwarding = 1

net.ipv4.conf.em4.mc_forwarding = 0

net.ipv4.conf.em2.forwarding = 1

net.ipv4.conf.em2.mc_forwarding = 0

net.ipv4.conf.em3.forwarding = 1

net.ipv4.conf.em3.mc_forwarding = 0

net.ipv4.conf.em1.forwarding = 1

net.ipv4.conf.em1.mc_forwarding = 0

net.ipv6.conf.all.forwarding = 0

net.ipv6.conf.all.mc_forwarding = 0

net.ipv6.conf.default.forwarding = 0

net.ipv6.conf.default.mc_forwarding = 0

net.ipv6.conf.lo.forwarding = 0

net.ipv6.conf.lo.mc_forwarding = 0

net.ipv6.conf.em1.forwarding = 0

net.ipv6.conf.em1.mc_forwarding = 0

net.ipv6.conf.em2.forwarding = 0

net.ipv6.conf.em2.mc_forwarding = 0

net.ipv6.conf.em3.forwarding = 0

net.ipv6.conf.em3.mc_forwarding = 0

net.ipv6.conf.em4.forwarding = 0

net.ipv6.conf.em4.mc_forwarding = 0

[root@linux-gateway ~]#