CentOS7 开启网卡自动获取IP

enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
inet 192.168.56.101  netmask 255.255.255.0  broadcast 192.168.56.255
inet6 fe80::a00:27ff:feaa:2638  prefixlen 64  scopeid 0x20<link>
ether 08:00:27:aa:26:38  txqueuelen 1000  (Ethernet)
RX packets 253  bytes 26083 (25.4 KiB)
RX errors 0  dropped 0  overruns 0  frame 0
TX packets 217  bytes 30197 (29.4 KiB)
TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
inet 127.0.0.1  netmask 255.0.0.0
inet6 ::1  prefixlen 128  scopeid 0x10<host>
loop  txqueuelen 0  (Local Loopback)
RX packets 4  bytes 340 (340.0 B)
RX errors 0  dropped 0  overruns 0  frame 0
TX packets 4  bytes 340 (340.0 B)
TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
inet 192.168.122.1  netmask 255.255.255.0  broadcast 192.168.122.255
ether 52:54:00:37:18:01  txqueuelen 0  (Ethernet)
RX packets 0  bytes 0 (0.0 B)
RX errors 0  dropped 0  overruns 0  frame 0
TX packets 0  bytes 0 (0.0 B)
TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0