Lab Topology Reference

The lab topology is described in a YAML file using a dictionary format. The three major components that should be present in every topology file are:

Other topology elements include:

  • provider – virtualization provider (default: libvirt)

  • groups – optional groups of nodes

  • module – default list of modules used by this network topology. You can use device-level module attribute to override this setting for individual nodes.

  • addressingIPv4 and IPv6 pools used to address management, loopback, LAN, P2P and stub interfaces

  • name – topology name (used in bridge names)

  • plugin – list of plugins used by this topology.

  • message – a help message to display after successful netlab initial or netlab up commands. You can use that message to tell the end-user how to use the lab (example: VLAN integration test cases).


  • All elements apart from nodes are optional – missing links element indicates a topology without inter-node links (just the management interfaces)

  • Default values of defaults and addressing elements are taken from default settings.

  • List of modules is used to specify additional initial configuration elements (example: OSPF routing)

  • Default topology name is the directory name.

You’ll find sample topology files in the tutorials.