docker-network-create

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NAME

   docker-network-create - Create a network

SYNOPSIS

   docker network create [OPTIONS] NETWORK

DESCRIPTION

   Creates a new network. The DRIVER accepts bridge or overlay which are the built-in network drivers. If you have installed a third party or your own custom network driver you can spec
   ify  that  DRIVER  here also. If you don't specify the --driver option, the command automatically creates a bridge network for you.  When you install Docker Engine it creates a bridge
   network automatically. This network corresponds to the docker0 bridge that Engine has traditionally relied on. When you launch a new container with  docker run it  automatically  con‐
   nects to this bridge network. You cannot remove this default bridge network, but you can create new ones using the network create command.

   $ docker network create -d bridge my-bridge-network

   Bridge  networks  are isolated networks on a single Engine installation. If you want to create a network that spans multiple Docker hosts each running an Engine, you must enable Swarm
   mode, and create an overlay network. To read more about overlay networks with Swarm mode, see " ⟨https://docs.docker.com/network/overlay/⟩.

   Once you have enabled swarm mode, you can create a swarm-scoped overlay network:

   $ docker network create --scope=swarm --attachable -d overlay my-multihost-network

   By default, swarm-scoped networks do not allow manually started containers to be attached. This restriction is added to prevent someone that has access to a non-manager  node  in  the
   swarm cluster from running a container that is able to access the network stack of a swarm service.

   The --attachable option used in the example above disables this restriction, and allows for both swarm services and manually started containers to attach to the overlay network.

   Network names must be unique. The Docker daemon attempts to identify naming conflicts but this is not guaranteed. It is the user's responsibility to avoid name conflicts.

Overlay network limitations

   You should create overlay networks with /24 blocks (the default), which limits you to 256 IP addresses, when you create networks using the default VIP-based endpoint-mode. This recom
   mendation  addresses limitations with swarm mode https://github.com/moby/moby/issues/30820. If you need more than 256 IP addresses, do not increase the IP block size. You can either
   use dnsrr endpoint mode with an external load balancer, or use multiple smaller  overlay  networks.  See  Configure  service  discovery  https://docs.docker.com/engine/swarm/network
   ing/#configure-service-discovery⟩ for more information about different endpoint modes.

Connect containers

   When you start a container, use the --network flag to connect it to a network.  This example adds the busybox container to the mynet network:

   $ docker run -itd --network=mynet busybox

   If you want to add a container to a network after the container is already running, use the docker network connect subcommand.

   You  can  connect  multiple  containers to the same network. Once connected, the containers can communicate using only another container's IP address or name.  For overlay networks or
   custom plugins that support multi-host connectivity, containers connected to the same multi-host network but launched from different Engines can also communicate in this way.

   You can disconnect a container from a network using the docker network disconnect command.

Specify advanced options

   When you create a network, Engine creates a non-overlapping subnetwork for the network by default. This subnetwork is not a subdivision of an existing network.  It is purely  for  ip-
   addressing purposes. You can override this default and specify subnetwork values directly using the --subnet option. On a bridge network you can only create a single subnet:

   $ docker network create --driver=bridge --subnet=192.168.0.0/16 br0

   Additionally, you also specify the --gateway --ip-range and --aux-address options.

   $ docker network create \
     --driver=bridge \
     --subnet=172.28.0.0/16 \
     --ip-range=172.28.5.0/24 \
     --gateway=172.28.5.254 \
     br0

   If you omit the --gateway flag the Engine selects one for you from inside a preferred pool. For overlay networks and for network driver plugins that support it you can create multiple
   subnetworks.  This  example uses two /25 subnet mask to adhere to the current guidance of not having more than 256 IPs in a single overlay network. Each of the subnetworks has 126 us
   able addresses.

   $ docker network create -d overlay \
     --subnet=192.168.10.0/25 \
     --subnet=192.168.20.0/25 \
     --gateway=192.168.10.100 \
     --gateway=192.168.20.100 \
     --aux-address="my-router=192.168.10.5" --aux-address="my-switch=192.168.10.6" \
     --aux-address="my-printer=192.168.20.5" --aux-address="my-nas=192.168.20.6" \
     my-multihost-network

   Be sure that your subnetworks do not overlap. If they do, the network create fails and Engine returns an error.

Bridge driver options

   When creating a custom network, the default network driver (i.e. bridge) has additional options that can be passed. The following are those options and the  equivalent  docker  daemon
   flags used for docker0 bridge:

   
    Option                                          Equivalent  Description                                     
   
    com.docker.network.bridge.name                  -           Bridge  name to be used when creating the Linux 
                                                                bridge                                          
   
    com.docker.network.bridge.enable_ip_masquerade  --ip-masq   Enable IP masquerading                          
   
    com.docker.network.bridge.enable_icc            --icc       Enable or Disable Inter Container Connectivity  
   
    com.docker.network.bridge.host_binding_ipv4     --ip        Default IP when binding container ports         
   
    com.docker.network.driver.mtu                   --mtu       Set the containers network MTU                  
   
    com.docker.network.container_iface_prefix       -           Set a custom prefix for container interfaces    
   

   The following arguments can be passed to docker network create for any network driver, again with their approximate equivalents to docker daemon.

   
    Argument    Equivalent    Description                                
   
    --gateway   -             IPv4 or IPv6 Gateway for the master subnet 
   
    --ip-range  --fixed-cidr  Allocate IPs from a range                  
   
    --internal  -             Restrict external access to the network    
   
    --ipv6      --ipv6        Enable IPv6 networking                     
   
    --subnet    --bip         Subnet for network                         
   

   For example, let's use -o or --opt options to specify an IP address binding when publishing ports:

   $ docker network create \
       -o "com.docker.network.bridge.host_binding_ipv4"="172.19.0.1" \
       simple-network

Network internal mode

   By default, when you connect a container to an overlay network, Docker also connects a bridge network to it to provide external connectivity. If you want to create an externally  iso
   lated overlay network, you can specify the --internal option.

Network ingress mode

   You  can  create the network which will be used to provide the routing-mesh in the swarm cluster. You do so by specifying --ingress when creating the network. Only one ingress network
   can be created at the time. The network can be removed only if no services depend on it. Any option available when creating an overlay network is  also  available  when  creating  the
   ingress network, besides the --attachable option.

   $ docker network create -d overlay \
     --subnet=10.11.0.0/16 \
     --ingress \
     --opt com.docker.network.driver.mtu=9216 \
     --opt encrypted=true \
     my-ingress-network

Run services on predefined networks

   You can create services on the predefined docker networks bridge and host.

   $ docker service create --name my-service \
     --network host \
     --replicas 2 \
     busybox top

Swarm networks with local scope drivers

   You  can  create  a swarm network with local scope network drivers. You do so by promoting the network scope to swarm during the creation of the network.  You will then be able to use
   this network when creating services.

   $ docker network create -d bridge \
     --scope swarm \
     --attachable \
     swarm-network

   For network drivers which provide connectivity across hosts (ex. macvlan), if node specific configurations are needed in order to plumb the network on each host, you will supply  that
   configuration via a configuration only network.  When you create the swarm scoped network, you will then specify the name of the network which contains the configuration.

   node1$ docker network create --config-only --subnet 192.168.100.0/24 --gateway 192.168.100.115 mv-config
   node2$ docker network create --config-only --subnet 192.168.200.0/24 --gateway 192.168.200.202 mv-config
   node1$ docker network create -d macvlan --scope swarm --config-from mv-config --attachable swarm-network

OPTIONS

   --attachable[=false]      Enable manual container attachment

   --aux-address=map[]      Auxiliary IPv4 or IPv6 addresses used by Network driver

   --config-from=""      The network from which to copy the configuration

   --config-only[=false]      Create a configuration only network

   -d, --driver="bridge"      Driver to manage the Network

   --gateway=[]      IPv4 or IPv6 Gateway for the master subnet

   -h, --help[=false]      help for create

   --ingress[=false]      Create swarm routing-mesh network

   --internal[=false]      Restrict external access to the network

   --ip-range=[]      Allocate container ip from a sub-range

   --ipam-driver="default"      IP Address Management Driver

   --ipam-opt=map[]      Set IPAM driver specific options

   --ipv6[=false]      Enable IPv6 networking

   --label=      Set metadata on a network

   -o, --opt=map[]      Set driver specific options

   --scope=""      Control the network's scope

   --subnet=[]      Subnet in CIDR format that represents a network segment

SEE ALSO

   docker-network(1)

Docker Community Aug 2024 DOCKER(1)