1、查看是否开启转发

cat  /proc/sys/net/ipv4/ip_forward
#返回1代表IP已开启

1 开启， 0 未开启

2、临时开启
echo 1 > /proc/sys/net/ipv4/ip_forward

3、永久开启
vim /etc/sysctl.conf
net.ipv4.ip_forward = 1 # 开启ipv4的流量转发

net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
#开启ipv6的流量转发

4、立即生效
sysctl -p /etc/sysctl.conf 或重启网络