In bridge mode, solve the problem that centos7 has no IP and cannot connect to the external network

1. If the gateway does not have an ip address, you can perform the following operations

Below is the gateway without ip address

Do the following

# 注意ens33是网关名称，看自己网关名称

sudo vi /etc/sysconfig/network-scripts/ifcfg-ens33 

Modify or add the value inside, and set the ip to a fixed IP (the network segment with the same address as the host)

BOOTPROTO=static # 原来是 dhcp 修改成 static

IPADDR=202.141.191.22 # 静态IP
GATEWAY=202.141.191.1 # 默认网关
NETMASK=255.255.255.0 # 子网掩码
DNS1=114.114.114.114 # DNS 配置
DNS2=8.8.8.8 #DNS 配置


ONBOOT=yes  # 原来是 no 修改成 yes

Restart the network

systemctl restart network

 View the contents of the sudo vi /etc/resolv.conf file

2. Mutual ping (host ping through centos, centosping through host), but cannot connect to the external network

Check the DNS of the corresponding network segment of the host

Add this DNS address to the ifcfg-ens file

sudo vi /etc/sysconfig/network-scripts/ifcfg-ens33 


DNS3=202.141.180.1

restart service

systemctl restart network

View the contents of the sudo vi /etc/resolv.conf file, and you will find an additional address

 If it still doesn't work, ua, you can try

Add the route-ens33 file in the /etc/sysconfig/network-scripts/ directory (ens33 is the name of the gateway)

The content inside is 202.141.191.22/24 via 202.141.191.1 dev ens33

The format is: (ip address via gateway (gateway) dev gateway)