Bridged Networking is a mode in which the Virtual Network Adapter is bridged to the Physical Network Adapter on the host machine. This means that the Virtual Machine will appear as an entity on the same network as the host machine, with the Virtual Machine getting its own IP address depending on the network setup.
Bridged networking can be used when you want your Virtual Machines to be a full network citizen, i.e. to be an equal to the host on the network; not to go through any form of NAT to the hosting environment.
Here’s how you can activate it in OpenVZ:
1. Install bridge-utils and Kernel support for bridging if you haven’t yet.
2. Create a bridge:
```
brctl addbr bridge_name
```
1. Enable forwarding:
```
echo 1 > /proc/sys/net/ipv4/ip_forward
```
1. Now moving forward, we add our ethernet interface (eth0/eth1/etc.) to bridge:
```
brctl addif bridge_name eth0
```
1. Bring up the bridge:
```
ifconfig bridge_name up
```
1. Once you have the bridge setup, update the VZ interface configuration (`/etc/vz/vznet.conf`) to use the bridge.
2. Restart the VZ service.
Please note that OpenVZ is a bit dated now, and installing it on a modern Linux kernel may pose some challenges. Consider using LXC/LXD or other container solution that is actively maintained.
