SRv6 Lab with netlab¶

netlab builds a network design, addressing, and topology from a high-level infrastructure-as-code description, deploys containers or virtual machines using containerlab or Vagrant, and configures the network devices. It's by far the most convenient way to get a working SRv6 lab, regardless of whether you want to practice configuring SRv6 or just kick its tires.

Prerequisites¶

• Install netlab
• Use netlab install containerlab ansible to install containerlab, Docker, and Ansible

Sample IS-IS + SRv6 Topology¶

Create a file topology.yml in an empty directory:

addressing:                     # Define IPv6 address pools
  p2p.ipv6: 2001:1::/48         # SRv6 requires ipv6 addresses on interfaces
  loopback.ipv6: 2001:db8::/48  # Loopback IPv6 addresses can't hurt ;)

defaults.device: frr            # We'll use FRRouting ...
provider: clab                  # ... containers orchestrated with containerlab

module: [ isis, srv6 ]          # All devices are running IS-IS and SRv6
nodes: [ pe1, p, pe2 ]          # The lab topology has three nodes
links: [ pe1-p, p-pe2 ]         # And two links between them

You don't need initial device configurations; netlab will:

• Design the IS-IS routing protocol (not too hard with three nodes and one area),
• Allocate IPv4 and IPv6 addresses to links and interfaces,
• Allocate SRv6 SIDs to individual nodes,
• Create interface, IS-IS, and SRv6 configurations for all devices,
• Deploy the configurations to FRRouting containers using a combination of bash and vtysh scripts.

Deploy¶

# Start the lab
netlab up

# Check lab status
netlab status

# Connect to a node
netlab connect pe1

# Destroy the lab
netlab down --cleanup

Useful netlab reports:

• netlab report devices -- nodes, node IDs, device types, and device images
• netlab report wiring -- lab nodes and links
• netlab report addressing -- lab addressing
• netlab report isis-nodes -- IS-IS routing
• netlab report mgmt -- Management access to lab devices

Check also netlab graphs (although the topology is trivial enough to visualize without one).

Sample IS-IS Topology¶

Use this topology (stored in topology.yml) if you want to practice SRv6 configuration in an already-configured IS-IS network:

addressing:                     # Define IPv6 address pools
  p2p.ipv6: 2001:1::/48         # SRv6 requires ipv6 addresses on interfaces
  loopback.ipv6: 2001:db8::/48  # Loopback IPv6 addresses can't hurt ;)

defaults.device: frr            # We'll use FRRouting ...
provider: clab                  # ... containers orchestrated with containerlab

module: [ isis ]                # All devices are running IS-IS and SRv6
nodes: [ pe1, p, pe2 ]          # The lab topology has three nodes
links: [ pe1-p, p-pe2 ]         # And two links between them

Verify SRv6¶

# Check SRv6 SIDs
netlab connect pe1 vtysh -c "show ipv6 route"

# Check IS-IS topology database
netlab connect pe1 vtysh -c "show isis database detail"

Ready-Made SRv6 Topologies¶

Instead of writing your own topology, you can start from the ipspace/srv6-examples collection — ready-to-run netlab topologies published by Ivan Pepelnjak (announcement) and organized in two tracks:

Introductory

Services

Each lab directory is self-contained; see the collection's getting started guide and the netlab SRv6 module for the list of supported platforms.

Further Reading¶

• Linux Kernel SRv6
• FRRouting
• netlab documentation
• Sample SRv6 lab topologies

References¶

1. netlab Documentation - Official netlab documentation site with installation, usage, and topology reference
2. netlab GitHub Repository - Source code, releases, and issue tracking for netlab
3. Sample netlab SRv6 lab topologies - Ready-to-run introductory and services topologies
4. Sample netlab SRv6 Lab Topologies (ipSpace.net) - Ivan Pepelnjak's announcement post for the srv6-examples collection
5. netlab 26.10 Release Notes - Release adding the SRv6 configuration module
6. More netlab Examples - Curated collection of lab topology examples for various network scenarios