Disable NAT for MGMT network

[c-po]

Hi,

I could not find anything in the documentation. When containerlab is started a new management network for docker is created with the management IP prefix.

Inspecting iptables I noticed that NAT is enabled for this prefix. As I wan't to use a routed mgmt network so I can access my lab nodes from external systems and also properly setup tacacs I would like to disable NAT.

Is there an easy way to disable MGMT network NAT in the topology definition?

Or is there a way to pass nerd know options to the docker driver like:

networks:
  network-name:
    driver: bridge
    driver_opts:
      com.docker.network.bridge.gateway_mode_ipv4: 'routed'

[hellt]

Hi there. Currently network options are not exposed. So for now it is a nat mode only :/

I have logged it as a feature req

#2269

[c-po]

Thank you @hellt, could you point me to the Go code where that magic happens?

[hellt]

it is all here for docker https://github.com/srl-labs/containerlab/blob/main/runtime/docker/docker.go

in particular

containerlab/runtime/docker/docker.go

Line 141 in 5e9647b

func (d *DockerRuntime) CreateNet(ctx context.Context) (err error) {