Chapter 3. Configuring a network bond

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:

   # 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 port-type bond con-name bond0-port1 ifname enp7s0 controller bond0
      # nmcli connection add type ethernet port-type bond con-name bond0-port2 ifname enp8s0 controller 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:

      1. Set the controller parameter of these connections to bond0:

         # nmcli connection modify bridge0 controller bond0
         # nmcli connection modify bridge1 controller bond0

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

      2. Reactivate the connections:

         # nmcli connection up bridge0
         # nmcli connection up bridge1

4. Configure the IPv4 settings:

   • To set a static IPv4 address, network mask, default gateway, and DNS server to the bond0 connection, enter:

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

   • To use DHCP, no action is required.
   • If you plan to use this bond device as a port of other devices, no action is required.

5. Configure the IPv6 settings:

   • To set a static IPv6 address, network mask, default gateway, and DNS server to the bond0 connection, enter:

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

   • To use stateless address autoconfiguration (SLAAC), no action is required.
   • If you plan to use this bond device as a port of other devices, no action is required.

6. Optional: If you want to set any parameters on the bond ports, use the following command:

   # nmcli connection modify bond0-port1 bond-port.<parameter> <value>

7. Activate the connection:

   # nmcli connection up bond0

8. 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 the bond is enabled:

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

      # nmcli connection modify bond0 connection.autoconnect-ports 1

   2. Reactivate the bridge:

      # nmcli connection up bond0

Verification

1. Temporarily remove the network cable from one of the network devices and check if the other device in the bond is handling the traffic.

   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. Select the Networking tab in the navigation on the left side of the screen.
2. Click Add bond in the Interfaces section.
3. Enter the name of the bond device you want to create.
4. Select the interfaces that should be members of the bond.

5. Select the mode of the bond.

   If you select Active backup, the web console shows the additional field Primary in which you can select the preferred active device.

6. Set the link monitoring mode. For example, when you use the Adaptive load balancing mode, set it to ARP.
7. Optional: Adjust the monitoring interval, link up delay, and link down delay settings. Typically, you only change the defaults for troubleshooting purposes.
8. Click Apply.

9. By default, the bond uses a dynamic IP address. If you want to set a static IP address:

   1. Click the name of the bond in the Interfaces section.
   2. Click Edit next to the protocol you want to configure.
   3. Select Manual next to Addresses, and enter the IP address, prefix, and default gateway.
   4. In the DNS section, click the + button, and enter the IP address of the DNS server. Repeat this step to set multiple DNS servers.
   5. In the DNS search domains section, click the + button, and enter the search domain.
   6. If the interface requires static routes, configure them in the Routes section.
   7. Click Apply

Verification

1. Select the Networking tab in the navigation on the left side of the screen, and check if there is incoming and outgoing traffic on the interface.

2. Temporarily remove the network cable from one of the network devices and check if the other device in the bond is handling the traffic.

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

3. Display the status of the bond:

   # cat /proc/net/bonding/bond0

Procedure

1. If you do not know the network device names on which you want configure a network bond, display the available devices:

   # nmcli device status
   DEVICE     TYPE      STATE                   CONNECTION
   enp7s0     ethernet  unavailable             --
   enp8s0     ethernet  unavailable             --
   ...

2. Start nmtui:

   # nmtui

3. Select Edit a connection, and press Enter.
4. Press Add.
5. Select Bond from the list of network types, and press Enter.

6. Optional: Enter a name for the NetworkManager profile to be created.

   On hosts with multiple profiles, a meaningful name makes it easier to identify the purpose of a profile.

7. Enter the bond device name to be created into the Device field.

8. Add ports to the bond to be created:

   1. Press Add next to the Ports list.
   2. Select the type of the interface you want to add as a port to the bond, for example, Ethernet.
   3. Optional: Enter a name for the NetworkManager profile to be created for this bond port.
   4. Enter the port’s device name into the Device field.
   5. Press OK to return to the window with the bond settings.
   6. Repeat these steps to add more ports to the bond.
9. Set the bond mode. Depending on the value you set, nmtui displays additional fields for settings that are related to the selected mode.

10. Depending on your environment, configure the IP address settings in the IPv4 configuration and IPv6 configuration areas accordingly. For this, press the button next to these areas, and select:

    • Disabled, if the bond does not require an IP address.
    • Automatic, if a DHCP server or stateless address autoconfiguration (SLAAC) dynamically assigns an IP address to the bond.

    • Manual, if the network requires static IP address settings. In this case, you must fill further fields:

      1. Press Show next to the protocol you want to configure to display additional fields.

      2. Press Add next to Addresses, and enter the IP address and the subnet mask in Classless Inter-Domain Routing (CIDR) format.

         If you do not specify a subnet mask, NetworkManager sets a /32 subnet mask for IPv4 addresses and /64 for IPv6 addresses.

      3. Enter the address of the default gateway.
      4. Press Add next to DNS servers, and enter the DNS server address.
      5. Press Add next to Search domains, and enter the DNS search domain.
11. Press OK to create and automatically activate the new connection.
12. Press Back to return to the main menu.
13. Select Quit, and press Enter to close the nmtui application.

Verification

1. Temporarily remove the network cable from one of the network devices and check if the other device in the bond is handling the traffic.

   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 content:

   ---
   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
       metric: 300
     - destination: ::/0
       next-hop-address: 2001:db8:1::fffe
       next-hop-interface: bond0
       metric: 300
   
   dns-resolver:
     config:
       search:
       - example.com
       server:
       - 192.0.2.200
       - 2001:db8:1::ffbb

   These settings define a network bond with the following settings:

   • Network interfaces in the bond: enp1s0 and enp7s0
   • Mode: active-backup
   • Static IPv4 address: 192.0.2.1 with a /24 subnet mask
   • Static IPv6 address: 2001:db8:1::1 with a /64 subnet mask
   • IPv4 default gateway: 192.0.2.254
   • IPv6 default gateway: 2001:db8:1::fffe
   • IPv4 DNS server: 192.0.2.200
   • IPv6 DNS server: 2001:db8:1::ffbb
   • DNS search domain: example.com

2. Apply the settings to the system:

   # nmstatectl apply ~/create-bond.yml

Verification

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. Create a playbook file, for example, ~/playbook.yml, with the following content:

   ---
   - name: Configure the network
     hosts: managed-node-01.example.com
     tasks:
       - name: Bond connection profile with two Ethernet ports
         ansible.builtin.include_role:
           name: redhat.rhel_system_roles.network
         vars:
           network_connections:
             # Bond profile
             - name: bond0
               type: bond
               interface_name: bond0
               ip:
                 dhcp4: yes
                 auto6: yes
               bond:
                 mode: active-backup
               state: up
   
             # Port profile for the 1st Ethernet device
             - name: bond0-port1
               interface_name: enp7s0
               type: ethernet
               controller: bond0
               state: up
   
             # Port profile for the 2nd Ethernet device
             - name: bond0-port2
               interface_name: enp8s0
               type: ethernet
               controller: bond0
               state: up

   The settings specified in the example playbook include the following:

   type: <profile_type>

   Sets the type of the profile to create. The example playbook creates three connection profiles: One for the bond and two for the Ethernet devices.

   dhcp4: yes

   Enables automatic IPv4 address assignment from DHCP, PPP, or similar services.

   auto6: yes

   Enables IPv6 auto-configuration. By default, NetworkManager uses Router Advertisements. If the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server.

   mode: <bond_mode>

   Sets the bonding mode. Possible values are:

   • balance-rr (default)
   • active-backup
   • balance-xor
   • broadcast
   • 802.3ad
   • balance-tlb
   • balance-alb.

   Depending on the mode you set, you need to set additional variables in the playbook.

   For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

2. Validate the playbook syntax:

   $ ansible-playbook --syntax-check ~/playbook.yml

   Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

3. Run the playbook:

   $ ansible-playbook ~/playbook.yml