The main topology in this lab is described in a YAML file `cvx-dcn.clab.yaml’. Here is a break down of the key components in the file:

• name: cdc: This specifies the name of the Containerlab environment, which stands for “Cumulus Data Centre.”

• topology: This section defines the topology of the network.

• The nodes section contains definitions for each node in the network. Nodes can represent various devices like switches, routers, or servers.
  • Each node is given a unique name (leaf01, spine01, etc.).
  • Each node has properties:
    • kind: Specifies the type of node. In this case, cvx and linux are used, representing Cumulus VX and Linux-based servers respectively.
    • image: Specifies the Docker image used for the node.
    • runtime: Specifies the runtime environment. Here, ‘docker’ is used instead of the default ‘ignite’for the reasons explained here.
    • binds: Specifies the volumes to mount into the container. This enables attaching files or folders on the host machine to the container.
    • mgmt-ipv4: Specifies the management IPv4 address of the node. All containers can communicate with each other via the default bridge ‘clab’. This is considered the management network.
    • group: Assigns nodes to specific groups. The group provides hints for visulizing the network.
• The links section defines the connections between nodes.
  • Each link connects two nodes using endpoints, which are specified as b[node_name:interface]. For example, leaf01:swp1 represents interface swp1 on node leaf01.
• The mgmt section specifies management-related configurations, in this case, it changes the default gateway IPv4 address.