Here’s a standard home network.  One external IP and one LAN.

To create a home lab without disturbing the peace, I needed to add an additional private network (two LANs), like this:

Setting this up would require an additional router, an additional switch and several Ethernet cables and NICs.  Here’s the problem with that: it’s a mess.  So, with a Latitude E6440 running ESXi and one Ethernet port I used this setup instead:

Connect the one physical NIC on the ESXi laptop to the physical switch on LAN1.

Setup two virtual switches.  vSwitch0 has the physical NIC attached to it and is the management network for your ESXi host.  vSwitch1 has no physical adapters.

Attach one VM to vSwitch0 and vSwitch1.  Attach all other VMs to vSwitch1.  Here’s my config:

Of course, vSwitch1 VMs can’t get out to the world yet and can’t even communicate with each other unless static IPs are set.  Windows RRAS will solve that problem next!