Introduction

This guide explains how to set up a Docker network of type ipvlan, allowing containers to communicate seamlessly as peers on the same physical network. The ipvlan mode offers enhanced flexibility by providing precise control over IP address management, gateway configuration, and network modes. This setup is particularly beneficial when containers need to interact directly with the local network infrastructure, much like traditional physical devices.

Whether you’re managing a small home lab or deploying complex containerized applications, understanding and configuring ipvlan can significantly improve your container networking. This guide covers the available configuration options, providing a comprehensive overview to help you manage your network efficiently.

Command to Create the Network

Use the following Docker command to create the ipvlan network:

sudo docker network create ipvlan \
  --scope="local" \  # Restrict network to local communication
  --driver="ipvlan" \  # Use ipvlan driver for networking
  --ipam-driver="default" \  # Use default IPAM driver for IP management
  --ipam-opt="" \  # (Optional) Custom IPAM options
  --subnet="192.168.1.0/24" \  # Set the subnet for the network
  --ip-range="192.168.1.128/25" \  # Specify range for containers
  --gateway="192.168.1.1" \  # Set the gateway IP
  --aux-address="web-server=192.168.1.2" \  # Assign static IPs for hosts
  --aux-address="db-server=192.168.1.3" \  # Assign static IPs for hosts
  --internal=false \  # Allow traffic to and from the internet
  --attachable=true \  # Allow containers to manually connect to the network
  --ingress=false \  # Not for use with Docker Swarm mode
  --config-from= \  # (Optional) Specify external config source
  --config-only=false \  # Ensure network and config are created
  --opt ipv6=disable \  # Disable IPv6 support
  --opt ipvlan_mode=l2 \  # Use Layer 2 mode for communication
  --opt parent=eno1 \  # Bind to the physical network interface eno1
  --label com.ipvlan.network.description="is a non-isolated network."  # Custom network label

Description of the Options

  • --scope="local": Limit the network to local communication.
    • Example: --scope="local" restricts the network to communication within a single host.
  • --driver="ipvlan": Use the ipvlan network driver.
    • Example: --driver="ipvlan" specifies that the ipvlan driver will be used to manage the network.
  • --ipam-driver="default": Use the default IPAM driver.
    • Example: --ipam-driver="default" uses Docker’s default IP address management for allocating IPs.
  • --ipam-opt="": Specify IPAM options (empty in this case).
    • Example: --ipam-opt="subnet=192.168.1.0/24" can be used to specify custom IPAM options like a custom subnet.
  • --subnet="192.168.1.0/24": The subnet for the network.
    • Example: --subnet="192.168.1.0/24" defines the range of IP addresses that will be used by the network.
  • --ip-range="192.168.1.128/25": The range of available IP addresses for containers.
    • Example: --ip-range="192.168.1.128/25" ensures containers only use IP addresses between 192.168.1.128 and 192.168.1.255.
  • --gateway="192.168.1.1": The IP address of the network gateway.
    • Example: --gateway="192.168.1.1" specifies the gateway IP that containers will use to access the outside network.
  • --aux-address: Specify specific IP addresses for hosts within the network.
    • Example:
      --aux-address="web-server=192.168.1.2"
--aux-address="db-server=192.168.1.3"
      These entries assign specific IP addresses (192.168.1.2, 192.168.1.3) to web-server and db-server, ensuring they have static IPs within the network.
  • --internal=false: Allow traffic to and from the internet.
    • Example: --internal=false enables external communication, allowing containers to access the internet.
  • --attachable=true: Allow containers to connect to this network.
    • Example: --attachable=true lets containers manually connect to the network via docker network connect.
  • --ingress=false: The network configuration is not intended for use with Docker’s Swarm mode.
    • Example: --ingress=false specifies that the network should not be used for Docker Swarm services.
  • --config-from=: Specify an external configuration source (not used in this example).
    • Example: --config-from="my_config" could be used when using a predefined configuration file to define the network settings.
  • --config-only=false: Not only create a configuration.
    • Example: --config-only=false ensures that both the network and its configuration are created.
  • --opt ipv6=disable: Disable IPv6.
    • Example: --opt ipv6=disable turns off IPv6 support, ensuring only IPv4 is used.
  • --opt ipvlan_mode=l2: Use Layer 2 mode for the network.
    • Example: --opt ipvlan_mode=l2 specifies that containers should communicate at the data link layer (Layer 2), similar to regular Ethernet devices.
  • --opt parent=eno1: The physical network interface on which the network is based.
    • Example: --opt parent=eno1 binds the network to the physical interface eno1 on your host.
      • How to find it: Run ip a to list all network interfaces on the host. Look for the name of the active network interface connected to your local network (e.g., eno1, eth0, or ens33).
  • --label com.ipvlan.network.description="is a non-isolated network.": A label to describe the network.
    • Example: --label com.ipvlan.network.description="is a non-isolated network." adds a custom label to help describe the network for organizational purposes.

Applications and Considerations

  • IPvlan Mode (L2): Using ipvlan_mode=l2 allows containers to communicate as peers on the same physical network.
  • Limitations: Ensure the specified network interface (eno1) is available and suitable for use with IPvlan. Verify it is up and properly configured.
  • Network Security: By setting --internal=false, containers can communicate outside the network, which is important for applications that require internet access.

Practical Example

To create a Docker network for a web application and a database, where the web server (web-server) and database server (db-server) are assigned static IPs:

sudo docker network create ipvlan \
  --scope="local" \
  --driver="ipvlan" \
  --subnet="192.168.2.0/24" \
  --ip-range="192.168.2.128/25" \
  --gateway="192.168.2.1" \
  --aux-address="web-server=192.168.2.2" \
  --aux-address="db-server=192.168.2.3" \
  --internal=false \
  --attachable=true \
  --opt ipvlan_mode=l2 \
  --opt parent=eno1

This setup assigns specific IP addresses to web-server and db-server while ensuring the containers can access the internet.


Conclusion

Using an ipvlan network in Docker offers benefits such as low-level network communication and IP address management. This is especially useful when containers need to function as ‘peers’ on the same physical network. However, be mindful of network interface availability and configuration. By understanding and configuring the various options, you can create a robust and flexible network tailored to your Docker containers.

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Last updated 26 Feb 2025, 16:08 CET . history