Use Macvlan networksEstimated reading time: 3 minutes
Some applications, especially legacy applications or applications which monitor
network traffic, expect to be directly connected to the physical network. In
this type of situation, you can use the
macvlan network driver to assign a MAC
address to each container’s virtual network interface, making it appear to be
a physical network interface directly connected to the physical network. In this
case, you need to designate a physical interface on your Docker host to use for
the Macvlan, as well as the subnet and gateway of the Macvlan. You can even
isolate your Macvlan networks using different physical network interfaces.
Keep the following things in mind:
- It is very easy to unintentionally damage your network due IP address exhaustion or to “VLAN spread”, which is a situation in which you have an inappropriately large number of unique MAC addresses in your network.
- Your networking equipment needs to be able to handle “promiscuous mode”, where one physical interface can be assigned multiple MAC addresses.
- If your application can work using a bridge (on a single Docker host) or overlay (to communicate across multiple Docker hosts), these solutions may be better in the long term.
Create a macvlan network
When you create a Macvlan network, it can either be in bridge mode or 802.1q trunk bridge mode.
In bridge mode,Macvlan traffic goes through a physical device on the host.
In 802.1q trunk bridge mode, traffic goes through an 802.1q sub-interface which Docker creates on the fly. This allows you to control routing and filtering at a more granular level.
To create a Macvlan network which bridges with a given physical network
--driver macvlan with the
docker network create command. You
also need to specify the
parent, which is the interface the traffic will
physically go through on the Docker host.
$ docker network create -d macvlan \ --subnet=172.16.86.0/24 \ --gateway=172.16.86.1 \ -o parent=eth0 pub_net
If you need to exclude IP addresses from being used in the Macvlan network, such
as when a given IP address is already in use, use
$ docker network create -d macvlan \ --subnet=192.168.32.0/24 \ --ip-range=192.168.32.128/25 \ --gateway=192.168.32.254 \ -o parent=eth0 macnet32
802.1q trunk bridge mode
If you specify a
parent interface name with a dot included, such as
Docker interprets that as a sub-interface of
eth0 and creates the sub-interface
$ docker network create -d macvlan \ --subnet=192.168.50.0/24 \ --gateway=192.168.50.1 \ -o parent=eth0.50 macvlan50
Use an ipvlan instead of macvlan
In the above example, you are still using a L3 bridge. You can use
instead, and get an L2 bridge. Specify
$ docker network create -d ipvlan \ --subnet=192.168.210.0/24 \ --subnet=192.168.212.0/24 \ --gateway=192.168.210.254 \ --gateway=192.168.212.254 \ -o ipvlan_mode=l2 ipvlan210
If you have configured the Docker daemon to allow IPv6, you can use dual-stack IPv4/IPv6 Macvlan networks.
$ docker network create -d macvlan \ --subnet=192.168.216.0/24 --subnet=192.168.218.0/24 \ --gateway=192.168.216.1 --gateway=192.168.218.1 \ --subnet=2001:db8:abc8::/64 --gateway=2001:db8:abc8::10 \ -o parent=eth0.218 \ -o macvlan_mode=bridge macvlan216
- Go through the macvlan networking tutorial
- Learn about networking from the container’s point of view
- Learn about bridge networks
- Learn about overlay networks
- Learn about host networking
- Learn about Macvlan networks