If you’ve ever wanted to build a realistic service provider lab topology without needing a rack full of hardware, Juniper logical systems are the answer. This introduction to the series explains what logical systems are, why they exist, and what you can do with them — all running on a single Juniper vMX image.
A Juniper logical system is a completely independent virtual router running inside a single physical or virtual device. Each one has its own routing tables, its own routing protocols, its own router ID, and its own independent control plane. It’s a step beyond routing instances — this isn’t just separate routing tables, this is a fully functional virtual router that behaves as if it were its own standalone device.
In this series we run nine virtual routers simultaneously on one vMX — CE1, PE1, PE2, PE3, PE4, a core router, and additional devices — all within a single running image. The topology is a realistic service provider network covering BGP, OSPF, MPLS and more. The vMX control plane runs on just four CPU cores and eight gigabytes of RAM per image. Rather than running nine separate images and consuming up to 72 gigabytes of RAM, logical systems let you do the same thing on a home PC with a fraction of the resources.
This video covers how the topology is structured, what each logical system represents in the broader network, and how the Juniper vMX handles the separation between them. We also look at the EVE-NG Pro topology overlay that maps each logical system to a visual node, and how to switch between logical system CLIs using the set CLI logical-system command.
Throughout the series we build out OSPF, ISIS, BGP, and MPLS step by step within this topology. By the time the series is complete you’ll have a fully functional multi-protocol service provider lab running on a single device — the kind of lab environment that would normally require significant hardware investment running comfortably on minimal resources.
Configuration files are provided with each video so you can follow along from any point in the series without having to replay every previous step.