How to create link aggregation

Note

These instructions assume a system setup based on the example configuration outlined in the Netplan tutorial.

Let’s suppose now that you need to configure your system to connect to your ISP links via a link aggregation. On Linux you can do that with a bond virtual interface.

On Netplan, an interface of type bond can be created inside a bonds mapping.

Now that the traffic will flow through the link aggregation, you will move all the addressing configuration to the bond itself.

You can define a list of interfaces that will be attached to the bond. In our simple scenario, we have a single one.

Edit the file /etc/netplan/second-interface.yaml and make the following changes:

network:
  version: 2
  ethernets:
    netplan-isp-interface:
      dhcp4: false
      dhcp6: false
      match:
        macaddress: 00:16:3e:0c:97:8a
      set-name: netplan-isp
  bonds:
    isp-bond0:
      interfaces:
        - netplan-isp-interface
      dhcp4: false
      dhcp6: false
      accept-ra: false
      link-local: []
      addresses:
        - 172.16.0.1/24
      routes:
        - to: default
          via: 172.16.0.254
      nameservers:
        search:
          - netplanlab.local
        addresses:
          - 172.16.0.254
          - 172.16.0.253

Note that you can reference the interface used in the bond by the name you defined for it in the ethernets section.

Now use netplan apply to apply your changes

netplan apply

Now your system has a new interface called isp-bond0. Use the command ip address show isp-bond0 or netplan status to check its state:

netplan status isp-bond0

You should see an output similar to the one below:

     Online state: online
    DNS Addresses: 127.0.0.53 (stub)
       DNS Search: lxd
                   netplanlab.local

●  4: isp-bond0 bond UP (networkd: isp-bond0)
      MAC Address: b2:6b:19:b1:9a:86
        Addresses: 172.16.0.1/24
    DNS Addresses: 172.16.0.254
                   172.16.0.253
       DNS Search: netplanlab.local
           Routes: default via 172.16.0.254 (static)
                   172.16.0.0/24 from 172.16.0.1 (link)

3 inactive interfaces hidden. Use "--all" to show all.