Configuring server network is always a fun. There is a good chance of getting disconnected from the remote servers if you’re working from a remote place on a production server. I have worked on OpenVZ for quite a long time now. But I had never got to customize its internal VE networking.
Last month I had to configure a eth device inside each VE, i.e an another LAN ip needs to be configured for each VPS which you configure inside the hardware node with a different subnet mask. Nothing but a Virtual LAN. I though it will be easy and started editing the network configuration files but found that all my changes will be wiped off if the VE is rebooted. So I had to make the changes at the node level. Following is a sample Network layout which I was trying to configure.
Image Source : OpenVZ Wiki
OpenVZ has got a nice wiki with detailed description of various networking scenarios and configuration. Though I got bit confused with briged networks, veth devices and other documentations initially, It was easy to follow the steps provided in this link to achieve the required results.
You can read the differences between venet and veth devices here.