A virtual host (vhost) is an additional IP address assigned to a computer. The main use of virtual hosts is in webhosting, where having a whole computer for just one IP (site) is very impractical. But since masking your true host on IRC with vanity domains and hostnames is very popular, virtual hosts are also very popular on shell servers.

Each computer connected to the internet always has a main IP address, the default address. This is the address that all applications connecting to sites elsewhere on the internet use by default.

When you want an application to appear as if its connecting from the IP of a virtual host, you have to specifically instruct the operating system (normally UNIX) that the application wants to use a specific virtual host IP address. This is set on a per-connection basis.

To make the EnergyMech use a virtual host IP address you have to explicitly tell it to. This is done with the VIRTUAL configuration command. This is set on a per-bot basis and this virtual host IP will be used whenever that bot tries to connect to an IRC server. The EnergyMech does not attempt to use the vhost for DCC and bot links.

If the EnergyMech fails to use a virtual host IP at any time, it will not try using that IP again until its restarted or assigned the IP again with the VIRTUAL (online) command.