The docker network ls command can be used to list networks.

docker network ls

Something like this should be returned.

NETWORK ID    NAME         DRIVER   SCOPE
r0zassvat4e5  foo-network  overlay  swarm
n3tno3xqjsu7  bar-network  overlay  swarm
ngfei70a2px2  network003   overlay  swarm

The docker network inspect command can be used to show more details about a network.

docker network inspect foo-network

Something like this should be returned.

[
    {
        "Name": "foo_network",
        "Id": "ownwg3iec3c95jxoeo7mn0lxp",
        "Created": "2021-07-15T09:08:00.883064327Z",
        "Scope": "swarm",
        "Driver": "overlay",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "10.0.12.0/24",
                    "Gateway": "10.0.12.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": null,
        "Options": {
            "com.docker.network.driver.overlay.vxlanid_list": "4109"
        },
        "Labels": {
            "com.docker.stack.namespace": "foo"
        }
    }
]