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DevOps Training » Docker » Docker Network » Bridge

Docker network supported by Bridge driver

• Lets create a user defined docker network docker network create

docker network create --driver bridge viki-alpine-net

• Inspect and notice that this network’s gateway is 172.20.0.1, as opposed to the default bridge network, whose gateway is 172.17.0.1.
• Docker uses the default 172.17.0.0/16 subnet for container networking. If this subnet is not available for docker in your environment (for example because your network already uses this subnet), you must configure Docker to use a different subnet.

vagrant@vagrant:~$ docker network inspect viki-alpine-net
[
    {
        "Name": "viki-alpine-net",
        "Id": "57284e7cd72cad3b25af2797103bf993f2f564308cc4a518a36573776b9bdc8e",
        "Created": "2020-01-22T04:11:46.780266369Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.20.0.0/16",
                    "Gateway": "172.20.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

• ifconfig on your docker host machine will also show you docker0 network intercace created by docker

• Lets create a custom subnet type docker network

docker network create \
  --driver=bridge \
  --subnet=172.28.0.0/16 \
  --ip-range=172.28.5.0/24 \
  --gateway=172.28.5.254 \
  viki-custom-apline-net

• You can connect any running container to this network

docker network connect viki-custom-apline-net alpine2

• You can also chose to connect the network while creating a container

  docker run -dit --name alpine1 --network viki-custom-apline-net alpine ash
  

• Now attach alpine1 and try to ping alpine2 from here, you will sucseed