Skip to content

Openvswitch bridge#

Similar to linux bridge capability, containerlab allows to connect nodes to an Openvswitch (Ovs) bridge. Ovs bridges offers even more connectivity options compared to classic Linux bridge, as well as it allows to create stretched L2 domain by means of tunneled interfaces (vxlan).

Using ovs-bridge kind#

Containerlab doesn't create bridges on users behalf, that means that in order to use a bridge in the topology definition file, the Ovs bridge needs to be created first.

Once the bridge is created, it has to be referenced as a node inside the topology file:

name: ovs

topology:
  nodes:
    myovs:
      kind: ovs-bridge
    ceos:
      kind: ceos
      image: ceos:latest
  links:
    - endpoints: ["myovs:ovsp1", "srl:eth1"]

In the example above, node myovs of kind ovs-bridge tells containerlab to identify it as a Ovs bridge and look for a bridge named myovs.

When connecting other nodes to a bridge, the bridge endpoint must be present in the links section.

Note

When choosing names of the interfaces that need to be connected to the bridge make sure that these names are not clashing with existing interfaces.
In the example above we attach a single interfaces named ovsp1 to the Ovs bridge with a name myovs. Before that, we ensured that no other interfaces named ovsp1 existed.

As a result of such topology definition, you will see the Ovs bridge br-clab with three interfaces attached to it:

❯ ovs-vsctl show
918a3466-4368-4167-9162-f2cf80a0c106
    Bridge myovs
        Port myovs
            Interface myovs
                type: internal
        Port eth1
            Interface ovsp1
    ovs_version: "2.13.1"


Back to top