Chapter 14. Configuring network bonding

Procedure

1. Create a bond interface:

   # nmcli connection add type bond con-name bond0 ifname bond0 bond.options "mode=active-backup"

   This command creates a bond named bond0 that uses the active-backup mode.

   To additionally set a Media Independent Interface (MII) monitoring interval, add the miimon=interval option to the bond.options property. For example, to use the same command but, additionally, set the MII monitoring interval to 1000 milliseconds (1 second), enter:

   # nmcli connection add type bond con-name bond0 ifname bond0 bond.options "mode=active-backup,miimon=1000"

2. Display the network interfaces, and note names of interfaces you plan to add to the bond:

   # nmcli device status
   DEVICE   TYPE      STATE         CONNECTION
   enp7s0   ethernet  disconnected  --
   enp8s0   ethernet  disconnected  --
   bridge0  bridge    connected     bridge0
   bridge1  bridge    connected     bridge1
   ...

   In this example:

   • enp7s0 and enp8s0 are not configured. To use these devices as ports, add connection profiles in the next step.
   • bridge0 and bridge1 have existing connection profiles. To use these devices as ports, modify their profiles in the next step.

3. Assign interfaces to the bond:

   1. If the interfaces you want to assign to the bond are not configured, create new connection profiles for them:

      # nmcli connection add type ethernet slave-type bond con-name bond0-port1 ifname enp7s0 master bond0
      # nmcli connection add type ethernet slave-type bond con-name bond0-port2 ifname enp8s0 master bond0

      These commands create profiles for enp7s0 and enp8s0, and add them to the bond0 connection.

   2. To assign an existing connection profile to the bond, set the master parameter of these connections to bond0:

      # nmcli connection modify bridge0 master bond0
      # nmcli connection modify bridge1 master bond0

      These commands assign the existing connection profiles named bridge0 and bridge1 to the bond0 connection.

4. Configure the IP settings of the bond. Skip this step if you want to use this bond as a port of other devices.

   1. Configure the IPv4 settings. For example, to set a static IPv4 address, network mask, default gateway, DNS server, and DNS search domain to the bond0 connection, enter:

      # nmcli connection modify bond0 ipv4.addresses '192.0.2.1/24'
      # nmcli connection modify bond0 ipv4.gateway '192.0.2.254'
      # nmcli connection modify bond0 ipv4.dns '192.0.2.253'
      # nmcli connection modify bond0 ipv4.dns-search 'example.com'
      # nmcli connection modify bond0 ipv4.method manual

   2. Configure the IPv6 settings. For example, to set a static IPv6 address, network mask, default gateway, DNS server, and DNS search domain to the bond0 connection, enter:

      # nmcli connection modify bond0 ipv6.addresses '2001:db8:1::1/64'
      # nmcli connection modify bond0 ipv6.gateway '2001:db8:1::fffe'
      # nmcli connection modify bond0 ipv6.dns '2001:db8:1::fffd'
      # nmcli connection modify bond0 ipv6.dns-search 'example.com'
      # nmcli connection modify bond0 ipv6.method manual

5. Activate the connection:

   # nmcli connection up bond0

6. Verify that the ports are connected, and the CONNECTION column displays the port’s connection name:

   # nmcli device
   DEVICE   TYPE      STATE      CONNECTION
   ...
   enp7s0   ethernet  connected  bond0-port1
   enp8s0   ethernet  connected  bond0-port2

   When you activate any port of the connection, NetworkManager also activates the bond, but not the other ports of it. You can configure that Red Hat Enterprise Linux enables all ports automatically when when the bond is enabled:

   1. Enable the connection.autoconnect-slaves parameter of the bond’s connection:

      # nmcli connection modify bond0 connection.autoconnect-slaves 1

   2. Reactivate the bridge:

      # nmcli connection up bond0

Verification steps

1. Temporarily remove the network cable from the host.

   Note that there is no method to properly test link failure events using software utilities. Tools that deactivate connections, such as nmcli, show only the bonding driver’s ability to handle port configuration changes and not actual link failure events.

2. Display the status of the bond:

   # cat /proc/net/bonding/bond0

Procedure

1. Open a terminal, and enter nm-connection-editor:

   $ nm-connection-editor

2. Click the + button to add a new connection.
3. Select the Bond connection type, and click Create.

4. In the Bond tab:

   1. Optional: Set the name of the bond interface in the Interface name field.

   2. Click the Add button to add a network interface as a port to the bond.

      1. Select the connection type of the interface. For example, select Ethernet for a wired connection.
      2. Optional: Set a connection name for the port.
      3. If you create a connection profile for an Ethernet device, open the Ethernet tab, and select in the Device field the network interface you want to add as a port to the bond. If you selected a different device type, configure it accordingly. Note that you can only use Ethernet interfaces in a bond that are not configured.
      4. Click Save.

   3. Repeat the previous step for each interface you want to add to the bond:

      

   4. Optional: Set other options, such as the Media Independent Interface (MII) monitoring interval.

5. Configure the IP settings of the bond. Skip this step if you want to use this bond as a port of other devices.

   1. In the IPv4 Settings tab, configure the IPv4 settings. For example, set a static IPv4 address, network mask, default gateway, DNS server, and DNS search domain:

      

   2. In the IPv6 Settings tab, configure the IPv6 settings. For example, set a static IPv6 address, network mask, default gateway, DNS server, and DNS search domain:

      

6. Click Save to save the bond connection.
7. Close nm-connection-editor.

Verification steps

1. Temporarily remove the network cable from the host.

   Note that there is no method to properly test link failure events using software utilities. Tools that deactivate connections, such as nmcli, show only the bonding driver’s ability to handle port configuration changes and not actual link failure events.

2. Display the status of the bond:

   # cat /proc/net/bonding/bond0

Procedure

1. Create a YAML file, for example ~/create-bond.yml, with the following contents:

   ---
   interfaces:
   - name: bond0
     type: bond
     state: up
     ipv4:
       enabled: true
       address:
       - ip: 192.0.2.1
         prefix-length: 24
       dhcp: false
     ipv6:
       enabled: true
       address:
       - ip: 2001:db8:1::1
         prefix-length: 64
       autoconf: false
       dhcp: false
     link-aggregation:
       mode: active-backup
       port:
       - enp1s0
       - enp7s0
   - name: enp1s0
     type: ethernet
     state: up
   - name: enp7s0
     type: ethernet
     state: up
   
   routes:
     config:
     - destination: 0.0.0.0/0
       next-hop-address: 192.0.2.254
       next-hop-interface: bond0
     - destination: ::/0
       next-hop-address: 2001:db8:1::fffe
       next-hop-interface: bond0
   
   dns-resolver:
     config:
       search:
       - example.com
       server:
       - 192.0.2.200
       - 2001:db8:1::ffbb

2. Apply the settings to the system:

   # nmstatectl apply ~/create-bond.yml

Verification steps

1. Display the status of the devices and connections:

   # nmcli device status
   DEVICE      TYPE      STATE      CONNECTION
   bond0       bond      connected  bond0

2. Display all settings of the connection profile:

   # nmcli connection show bond0
   connection.id:              bond0
   connection.uuid:            79cbc3bd-302e-4b1f-ad89-f12533b818ee
   connection.stable-id:       --
   connection.type:            bond
   connection.interface-name:  bond0
   ...

3. Display the connection settings in YAML format:

   # nmstatectl show bond0

Procedure

1. If the host on which you want to execute the instructions in the playbook is not yet inventoried, add the IP or name of this host to the /etc/ansible/hosts Ansible inventory file:

   node.example.com

2. Create the ~/bond-ethernet.yml playbook with the following content:

   ---
   - name: Configure a network bond that uses two Ethernet ports
     hosts: node.example.com
     become: true
     tasks:
     - include_role:
         name: rhel-system-roles.network
   
       vars:
         network_connections:
           # Define the bond profile
           - name: bond0
             type: bond
             interface_name: bond0
             ip:
               address:
                 - "192.0.2.1/24"
                 - "2001:db8:1::1/64"
               gateway4: 192.0.2.254
               gateway6: 2001:db8:1::fffe
               dns:
                 - 192.0.2.200
                 - 2001:db8:1::ffbb
               dns_search:
                 - example.com
             bond:
               mode: active-backup
             state: up
   
           # Add an Ethernet profile to the bond
           - name: bond0-port1
             interface_name: enp7s0
             type: ethernet
             controller: bond0
             state: up
   
           # Add a second Ethernet profile to the bond
           - name: bond0-port2
             interface_name: enp8s0
             type: ethernet
             controller: bond0
             state: up

3. Run the playbook:

   • To connect as root user to the managed host, enter:

     # ansible-playbook -u root ~/bond-ethernet.yml

   • To connect as a user to the managed host, enter:

     # ansible-playbook -u user_name --ask-become-pass ~/bond-ethernet.yml

     The --ask-become-pass option makes sure that the ansible-playbook command prompts for the sudo password of the user defined in the -u user_name option.

   If you do not specify the -u user_name option, ansible-playbook connects to the managed host as the user that is currently logged in to the control node.

Procedure

1. Create a bond interface in active-backup mode:

   # nmcli connection add type bond con-name bond0 ifname bond0 bond.options "mode=active-backup"

   This command names both the interface and connection profile bond0.

2. Configure the IPv4 settings of the bond:

   • If a DHCP server in your network assigns IPv4 addresses to hosts, no action is required.

   • If your local network requires static IPv4 addresses, set the address, network mask, default gateway, DNS server, and DNS search domain to the bond0 connection:

     # nmcli connection modify bond0 ipv4.addresses '192.0.2.1/24'
     # nmcli connection modify bond0 ipv4.gateway '192.0.2.254'
     # nmcli connection modify bond0 ipv4.dns '192.0.2.253'
     # nmcli connection modify bond0 ipv4.dns-search 'example.com'
     # nmcli connection modify bond0 ipv4.method manual

3. Configure the IPv6 settings of the bond:

   • If your router or a DHCP server in your network assigns IPv6 addresses to hosts, no action is required.

   • If your local network requires static IPv6 addresses, set the address, network mask, default gateway, DNS server, and DNS search domain to the bond0 connection:

     # nmcli connection modify bond0 ipv6.addresses '2001:db8:1::1/64'
     # nmcli connection modify bond0 ipv6.gateway '2001:db8:1::fffe'
     # nmcli connection modify bond0 ipv6.dns '2001:db8:1::fffd'
     # nmcli connection modify bond0 ipv6.dns-search 'example.com'
     # nmcli connection modify bond0 ipv6.method manual

4. Display the connection profiles:

   # nmcli connection show
   NAME             UUID                                  TYPE      DEVICE
   Docking_station  256dd073-fecc-339d-91ae-9834a00407f9  ethernet  enp11s0u1
   Wi-Fi            1f1531c7-8737-4c60-91af-2d21164417e8  wifi      wlp61s0
   ...

   You require the names of the connection profiles and the Ethernet device name in the next steps.

5. Assign the connection profile of the Ethernet connection to the bond:

   # nmcli connection modify Docking_station master bond0

6. Assign the connection profile of the Wi-Fi connection to the bond:

   # nmcli connection modify Wi-Fi master bond0

7. If your Wi-Fi network uses MAC filtering to allow only MAC addresses on a allow list to access the network, configure that NetworkManager dynamically assigns the MAC address of the active port to the bond:

   # nmcli connection modify bond0 +bond.options fail_over_mac=1

   With this setting, you must set only the MAC address of the Wi-Fi device to the allow list instead of the MAC address of both the Ethernet and Wi-Fi device.

8. Set the device associated with the Ethernet connection as primary device of the bond:

   # nmcli con modify bond0 +bond.options "primary=enp11s0u1"

   With this setting, the bond always uses the Ethernet connection if it is available.

9. Configure that NetworkManager automatically activates ports when the bond0 device is activated:

   # nmcli connection modify bond0 connection.autoconnect-slaves 1

10. Activate the bond0 connection:

    # nmcli connection up bond0