apt install docker.io

root@docker-01:~# docker version
Client:
 Version:           20.10.7
 API version:       1.41
 Go version:        go1.13.8
 Git commit:        20.10.7-0ubuntu5~20.04.2
 Built:             Mon Nov  1 00:34:17 2021
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server:
 Engine:
  Version:          20.10.7
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.13.8
  Git commit:       20.10.7-0ubuntu5~20.04.2
  Built:            Fri Oct 22 00:45:53 2021
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.5.5-0ubuntu3~20.04.1
  GitCommit:
 runc:
  Version:          1.0.1-0ubuntu2~20.04.1
  GitCommit:
 docker-init:
  Version:          0.19.0
  GitCommit

root@docker-01:~# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
b673f042244a   bridge    bridge    local
3a3afb03fab6   host      host      local
9b00fa0616f2   none      null      local

Bridge genauer ansehen

root@docker-01:~# docker network inspect b673f042244a
[
    {
        "Name": "bridge",
        "Id": "b673f042244a6aa8a717dc8f2975736b5dc511486378a84a0d6ad50af29a9a00",
        "Created": "2021-12-15T15:42:58.442593064+01:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

Problem ist gern das große Netzwerk das hier angelegt wird. Die meiste Zeit braucht man so ein großes Netzwerk nicht.