ESXi 8 dropped support for many legacy NICs (like Realtek or old Broadcom BCM5720). Fix: You need a custom ISO with Community Networking Drivers (fling) . Search for "ESXi 8 community driver fling" if your consumer-grade NIC isn't recognized.
Downloading the has changed significantly following Broadcom's acquisition of VMware. While the free version was briefly discontinued, Broadcom reintroduced it with the release of ESXi 8.0 Update 3e . Where to Download the ISO
For $210/year, you get keys for ESXi 8, vCenter, and other tools for homelab use . They redirect you to the official ISO, plus provide keys.