Linux

i have a single box i use for data storage; backup; wifi; router; and switch.

it runs ubuntu on the bare iron with

• a windows 10 kvm/qemu vm with pci pass through on wifi to get 1 gig wifi speeds on intel in ap mode (intel won't allow it using linux drivers)
• a pfsense kvm/qemu vm for router & firewall to internet and with pci pass through on a 1 gig nic to gap the internet from the base ubuntu
• dns & ip masquerade along with kvm/qemu based sofware defined networking for windows, pfsense and ubuntu to forward all wifi and cabled network through to internet and
• connected via 3 gig nic and switch for much faster local data storage and backup on the ubuntu install.
• vpn and remote backup using pfsense for access to my setup from anywhere else in the world. (eg routing traffic from the office to my home connection for personal use and access to my data)

topographically, it looks like this, but in reality it's all one box:

                              ┌────┐                    ┌─────────────┐                             
          ┌───────────────────┤vpn │ ┌──────────────────┤windows (wifi│                             
          ▼                   └────┘ │                  └─────────────┘                             
┌──────────┐                         │                                                              
│ internet │                         │                                                              
└──────────┘                         ▼                  ┌───────┐        ┌──────┐      ┌───────────┐
          ▲                ┌─────────┐                  │ubuntu │◄───────┤switch│◄─────┤  backups  │
          └────────────────┤ pfsense │◄─────────────────┴───────┘        └──────┘      └───────────┘
                           └─────────┘