Free resources
Networking
Routers, NAT, DHCP, DNS, VLANs and tunnels, built inside one virtual machine.
Hands-on labs
Labs
Every lab is a real environment with a terminal beside it, nothing to install. Each has a short basic lesson that shows how a lesson works with a lab. A free account runs every lab and is given the basic lessons on Home; with no account you can run the Git lab and the SQL lab.
Ubuntu VM lab
Static routing lab: build routes on a small network in your browser
A static routing lab: two routers and two hosts built inside one VM, with FRRouting and vtysh, and a script that marks it. Free sample; definition on GitHub.
Free lessons
- Static Routing Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
OSPF lab: bring up dynamic routing on three routers in your browser
An OSPF lab: three routers and two hosts in one VM, FRRouting and vtysh, watch hellos with tcpdump, and a script that marks it. Free sample; code on GitHub.
Free lessons
- OSPF Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
BGP lab: connect two autonomous systems in your browser
A BGP lab: two autonomous systems, AS 65001 and 65002, as routers in one VM with FRRouting, and a script that marks it. Free sample; the code is on GitHub.
Free lessons
- BGP Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
NAT gateway lab: masquerade and port forwarding with nftables in your browser
A NAT lab in one VM: a private host, a gateway and an outside server. Students set masquerade and a port forward with nftables. Marked by a script; free sample.
Free lessons
- NAT Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
DHCP and DNS lab: configure dnsmasq for a small network in your browser
A DHCP and DNS lab: students configure dnsmasq so two clients get leases, a fixed address and local names, on a private Ubuntu VM. Free sample.
Free lessons
- DHCP and DNS Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
VLAN lab: VLANs and inter-VLAN routing on one Ubuntu VM in your browser
A VLAN lab: students configure a switch, 802.1Q subinterfaces on a router on a stick and a firewall rule inside one Ubuntu VM, marked by a script.
Free lessons
- VLAN Basics
How it works · Source on GitHub · Sign up free for the lesson
Ubuntu VM lab
WireGuard lab: build a VPN tunnel between two sites in your browser
A WireGuard lab: students build a VPN tunnel between two sites inside one Ubuntu VM, with keys and routes, marked by a script. Free sample.
Free lessons
- WireGuard Basics
How it works · Source on GitHub · Sign up free for the lesson
Basic lessons are given to every free account, on Home, and to every college. Curriculum lessons, such as T Level, are for colleges. Labs marked as an Ubuntu VM lab are set by a teacher in a module, and their lessons start the VM for you.
Run these yourself
A free personal account runs every lab here and its lesson. Teaching a class? Start a college and set them for your students.
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