VCL network question

[ogroot]

The VCL cluster how-to wiki specifically says that a high speed LAN should be used and not WAN or VPN. I assumed that WAN and VPN should not be used due to bandwidth limitations. but.... does this mean that the master and slave computers must reside within the same subnet, or can the master communicate to the slaves across a layer 3 network?

example:
master exists in 192.168.1.0/24
slaves exist in 192.168.2.0/24
Both subnets will be local and not traversing the internet.

Also, what TCP port range does vcl use?

Thanks in advance for any help!