Virtual lab made of 3 Juniper vSRX routers running RIP v.2 routing protocol, brought up through Vagrant. Lab topology as per Day One: Routing the Internet Protocol Juniper book, page 34.

Use the commnand line to communicate directly with the routers like in real world setups.

Expand on this to experiment with other network topologies and routing protocols. Juniper vSRX routers support RIP, OSPF, IS, etc.

Or move on to a network simulator such as GNS3 or others.