Centos7默认安装是没有开启配置网卡信息的，无法访问外网。

下边配置打开网络自动获取Ip地址

1.查看网卡信息

执行Ifconfig

eno16777736: flags=4163
     
        mtu 1500        inet6 fe80::20c:29ff:fee8:8637  prefixlen 64  scopeid 0x20
              ether 00:0c:29:e8:86:37  txqueuelen 1000  (Ethernet)        RX packets 1121  bytes 98968 (96.6 KiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 179  bytes 25233 (24.6 KiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0lo: flags=73
      
         mtu 65536        inet 127.0.0.1  netmask 255.0.0.0        inet6 ::1  prefixlen 128  scopeid 0x10
       
                loop  txqueuelen 0  (Local Loopback)        RX packets 900  bytes 78372 (76.5 KiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 900  bytes 78372 (76.5 KiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
       
      
     

eno16777736代表网卡的名称，ether 00:0c:29:e8:86:37代表网卡的Mac地址 2.配置网卡开始网络连接 cd /etc/system/network-scripts/ vi ifcfg-eno16777736

HWADDR=00:0C:29:E8:86:37TYPE=EthernetBOOTPROTO=dhcpDEFROUTE=yesPEERDNS=yesPEERROUTES=yesIPV4_FAILURE_FATAL=noIPV6INIT=yesIPV6_AUTOCONF=yesIPV6_DEFROUTE=yesIPV6_PEERDNS=yesIPV6_PEERROUTES=yesIPV6_FAILURE_FATAL=noNAME=eno16777736UUID=79d6c916-aab8-45e4-a163-37ae73393d26ONBOOT=no

将ONBOOT= no改成ONBOOT=yes

3.重启网络

service network restart

4.再执行ifconfig

eno16777736: flags=4163
     
        mtu 1500        inet 192.168.159.128  netmask 255.255.255.0  broadcast 192.168.159.255        inet6 fe80::20c:29ff:fee8:8637  prefixlen 64  scopeid 0x20
              ether 00:0c:29:e8:86:37  txqueuelen 1000  (Ethernet)        RX packets 1699  bytes 140091 (136.8 KiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 333  bytes 42669 (41.6 KiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0lo: flags=73
      
         mtu 65536        inet 127.0.0.1  netmask 255.0.0.0        inet6 ::1  prefixlen 128  scopeid 0x10
       
                loop  txqueuelen 0  (Local Loopback)        RX packets 900  bytes 78372 (76.5 KiB)        RX errors 0  dropped 0  overruns 0  frame 0        TX packets 900  bytes 78372 (76.5 KiB)        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
       
      
     

inet 192.168.159.128 代表IP地址