That gives me an extra ethernet port that I use for VEP and I use a Thunderbolt to Ethernet adapter for the internet connection when I want fast internet. You could do what I did, which is to buy the OWC Thunderbolt 2 Dock. It just doesn’t work out in the long run. Now what if you’re using a laptop as your main machine? In that case, you should use the ethernet port for VEP connected via a private, closed ethernet switch along with the other VEP machines, and use WiFi for internet.
I particularly like this config with Windows computers because, since it’s not on the internet, there is no need for anti-virus which can slow the shit out of a machine. Most of the time, this doesn’t matter because you only need to go online to do a few updates now and then. One thing to know: when configured this way, the slave VEP machines can’t go on the internet unless they also have a secondary connection( like WiFi or a 2nd ethernet port).
Putting the VEP machines on a private, closed switch prevents all of those effects and allow both the internet and the VEP networks to function at full efficiency without interfering with each other. The reason we do it this way is because VEP eats up a tremendous amount of bandwidth on a network, and mixing its packets with regular packets from internet connected computers can cause all kinds of deleterious effects - stalling, hangs, dropouts, packet resend requests, packet collisions, general slowness, buffering, etc. Those 2 fields are for traversing the internet and have no bearing on a local network. There is no Routing, and there is no need for DNS. With the networking assignments in System Prefs for the VEP ethernet port, only 2 of the fields need to be filled: IP Address (manually specified) and Subnet Mask (which should be 255.255.255.0). You’ll see this “self-assigned” address when you lose internet connection, for example. It is used for link-local addresses between two hosts on a single link (direct, no routing) when no IP address(es) is(are) otherwise specified. I’ve seen people use this subnet for VEP, but I find it to be very unpredictable. There are several subnets ranges reserved for the LAN (used for local communications within a private network) and are not allowed on the WAN. The useable numbers for the fourth octet, as it’s called, is any number from 2 to 254. Set each VEP computer to a different IP address on the private VEP subnet (i.e. In other words, if your internet router is using the 192.168.1.x subnet, put the VEP network on something else - 192.168.25.x, for example. Set the VEP port to a static IP using a different subnet. You can use any setting that works (Manual, DHCP, etc.) for the internet connected port.
The best practice for a Mac Pro that has two ethernet ports is to connect one port to your house network that is internet connected, and connect the other port to a separate, closed gigabit ethernet switch that only connects to other VEP machines and does not connect to the internet. I always set static IPs on all machines involved in the VEP network. In my setup I use wi-fi for internet connections on both master and slave computers, and the VEP connection is a cat 6 cable from the laptop (via a Thunderbolt to Ethernet adapter) to the slave computer. In Mac world the set up he describes takes place in system preferences / network.
It references MACs, but I think the general advice about setting up a private LAN just for VEP are useful in both worlds. A friend shared this detailed best practices info for setting up IP addresses on a slave.