A VLAN acts like a private gigabit ethernet switch connecting your servers together via a second virtual ethernet card in each server. This network is isolated from the internet and other customers.
Bandwidth over a VLAN is not chargeable!
To make use of VLAN, first purchase a private VLAN subscription. Then add it to your account in the control panel. Then, edit each server’s configuration to use your private VLAN. This is under the Advanced settings in the Control Panel.