I have slowly but surely put together a home lab with old computers, It all started when I bought a new computer there sometime around 2007. I took the old computer and installed windows server 2003, set up an ftp & web server. At that time I didn't have a fixed IP, so I had to get around it with the help of a service like 'no-ip', but over time
I changed internet provider, and today I have access to 10 public IP addresses, and 500 Mbit up & down speed. Over the years I have replaced the old darorn and upgraded with real servers, have a couple of HP ML350 gen5, an HP DL580 gen5, HP ProLiant DL380 G6 , SuperMicro 3U case 12 hd, a SuperMicro 1U dual node, 3 home-built servers with SuperMicro motherboards, QNAP TS-869L NAS 8-Bay, Asustor AS6210T, Check Point Firewall T-120 OPNsense and a little more goodies in the rack. Recently I upgraded the entire network to Ubiquiti, A Ubiquiti Dream Machine Pro, Unifi Switch 48, 4 switches & 4 wifi access points. Almost all the servers run ProxMox, except fore one Citrix XenServer and a VMware ESXi server, it is labled with everything from OS to network structure, various web server systems, Kubernetes, Pi-Hole, wireguard, Docker and much more.