netlab release 25.09 includes:

• Link impairment (implemented with Linux netem queuing discipline) defined in lab topology or configured/controlled with the netlab tc command
• Configurable IPv6 Router Advertisement parameters
• The files plugin to store the content of short files (including custom configuration templates) directly in the lab topology
• Support for Nokia SR-OS container (SR-SIM)
• Support for very large topologies (tested so far: approximately 3000 lab devices)

But wait, there’s more (as always):

• Stefano Sasso implemented EVPN VLAN bundle service on Junos and Aruba CX
• You can enable debugging on Cisco IOS and FRR devices when starting the lab
• isis-nodes report (available as text, Markdown, or HTML) describes IS-IS nodes, areas, system IDs, and IS-types
• ssh_config report creates an SSH configuration file you can use to establish SSH sessions with the lab devices using the netlab server as a proxy host.

We also added the isis graph type that creates a graph of IS-IS routing (including areas, color-coded circuit types, and stub networks) as well as a half-dozen other graphing goodies:

• Graph titles can be defined with the graph.title topology parameter
• BGP graphs can display a subset of address families. They can also display local-as IBGP and confederation EBGP sessions, or style VRF BGP sessions as dashed lines.
• You can set color, width, and fill attributes on nodes and links.

Finally, the performance improvements (most notable in large topologies with hundreds of nodes):

• Shared container files (for example, /etc/hosts shared across all Linux and FRR containers) reduce the lab creation time by a factor of three
• The pickle snapshot file (replacing a YAML file) reduces the start time of various netlab commands by a factor of almost ten
• Cached Jinja2 templates also don’t hurt (they drastically sped up the integration test reports).

Want even more goodies? Explore the release notes.

Upgrading or Starting from Scratch?

• To upgrade your netlab installation, execute pip3 install --upgrade networklab.
• New to netlab? Start with the Getting Started document and the installation guide.
• Need help? Open a discussion or an issue in netlab GitHub repository.