Hi, I encountered a problem when creating a VLAN interface according to the Red_Hat_Enterprise_Linux-7-Networking_Guide. I configuered the parent interface ifcfg-eno1 as follows: DEVICE=eno1 TYPE=Ethernet BOOTPROTO=none ONBOOT=yes And I created a new file named ifcfg-eno1.5, the content is: DEVICE=eno1.5 BOOTPROTO=none ONBOOT=yes IPADDR=192.168.81.3 PREFIX=24 NETWORK=192.168.81.0 VLAN=yes Then I restarted the network: systemctl restart network After that I found that I couldn't connect to the Internet, even couldn't ping the gateway. I thought it might be I didn't set the GATEWAY in ifcfg-eno1.5, so I added the GATEWAY=192.168.81.254(My local area network gateway), it didn't work. Could anybody teach me how to create a VLAN interface in CentOS7, or tell me what' s wrong with my configuration, more detailed more better. Thanks Li yulei