Lab Environments Part 2: The Hypervisor Foundation

Part 1 laid out the taxonomy this series follows and named the real bottleneck, vendor image licensing, before any platform gets chosen. This part covers the layer underneath almost everything else in the series: the hypervisor most of the tools in Parts 3 and 4 run on top of as a guest, rather than a standalone install.

Type-1 versus type-2, and why the distinction matters for a lab specifically.

A type-1 (bare-metal) hypervisor runs directly on hardware with no host OS underneath it. A type-2 (hosted) hypervisor runs as an application on top of an existing OS, Windows, macOS, or Linux. For a lab, that distinction decides where the lab lives. A type-1 host gives you dedicated compute to run everything else on, EVE-NG or GNS3 or CML as a VM, or containerlab directly on the host OS. A type-2 hypervisor gives you a lab on the same laptop or desktop you already use for everything else, at the cost of sharing resources with whatever else that machine is doing.

Proxmox VE.

Free, AGPLv3, fully open source, built on KVM for full virtualization and LXC for containers, managed through a web GUI. This is what the pve host behind the Sn1per and BloodHound lab work runs, using named Linux bridges (vmbr-sniperlab, vmbr-msflab) to keep each lab network isolated from the others. Proxmox VE 9.2, released May 2026, moved to a Debian 13 “Trixie” base and added a Dynamic Load Balancer for automatically migrating HA workloads based on observed cluster load, expanded software-defined networking with WireGuard as a fabric protocol and EVPN route maps, and IPv6 underlay support.

The subscription question comes up constantly and the answer is simple: the feature set is identical with or without one. HA clustering, live migration, Ceph, the firewall, none of it is feature-gated. A subscription buys access to the Enterprise repository (more conservatively tested packages) and vendor support. The No-Subscription repository carries the same packages with no key required, and is explicitly fine for home labs, testing, and non-critical production. For a lab, that means Proxmox costs nothing and loses nothing by skipping the subscription.

ESXi.

VMware’s own bare-metal type-1 hypervisor, with a genuinely messy recent history worth stating plainly rather than glossing over. Broadcom discontinued the free standalone ESXi hypervisor in February 2024, as part of folding VMware’s whole product line into subscription-only VCF bundles after the acquisition. It came back in April 2025, and as of this writing ESXi 8.0 Update 3e is available as a free standalone hypervisor again, running an unlimited number of VMs within hardware limits, managed through the vSphere Host Client. Free ESXi on its own is genuinely usable for a home lab. The catch is that everything above bare ESXi, vCenter, vSphere clustering, the rest of the VMware stack, sits behind the same subscription-only VCF licensing that triggered the 2024 discontinuation in the first place. If the goal is specifically practicing VMware admin skills, or a job requires vSphere-specific behavior, ESXi is the right choice for that reason alone. Otherwise Proxmox covers the same ground (KVM virtualization, a web GUI, HA and live migration) without the same licensing back-and-forth.

VMware Workstation Pro (and Fusion, the macOS equivalent).

Type-2, and the terms changed significantly in 2025: Workstation Pro has been completely free for personal, educational, and commercial use since March 2025, no subscription or license key required, with all the features previously reserved for the paid edition included. The one friction point is distribution, not cost: downloads now require a Broadcom account, there’s no more anonymous download link. This is the natural choice when the lab needs to live on the same machine used for daily work rather than on dedicated hardware, and several of the tools in Part 3 (the GNS3 VM, EVE-NG’s ISO) run perfectly well as a guest inside Workstation or Fusion.

Where this leaves the choice.

Spare hardware and no specific reason to want VMware skills: Proxmox, for the identical reasons the pve host already runs it, no feature gate, an open license, and a bridge-per-lab pattern that scales cleanly as more labs get added. Spare hardware and a specific need for vSphere behavior: ESXi, accepting that anything beyond bare-metal ESXi means engaging with VCF licensing. No spare hardware, the lab has to share a laptop or desktop with everything else: Workstation or Fusion.

Either way, this layer is infrastructure, not the network lab itself. Part 3 picks up what actually runs on top of it: EVE-NG, GNS3, and pnetlab, the platforms that turn this compute into a topology of real vendor devices.