Chapter 8. Configuring network bonds using the web console

Learn how network bonding works and configure network bonds in the RHEL 8 web console.

Note

The RHEL 8 web console is build on top of the NetworkManager service.

For details, see Getting started with NetworkManager for managing networking.

Prerequisites

8.1. Understanding network bonding

Network bonding is a method to combine or aggregate network interfaces to provide a logical interface with higher throughput or redundancy.

The active-backup, balance-tlb, and balance-alb modes do not require any specific configuration of the network switch. However, other bonding modes require configuring the switch to aggregate the links. For example, Cisco switches requires EtherChannel for modes 0, 2, and 3, but for mode 4, the Link Aggregation Control Protocol (LACP) and EtherChannel are required.

For further details, see the documentation of your switch and Linux Ethernet Bonding Driver HOWTO.

Important

Certain network bonding features, such as the fail-over mechanism, do not support direct cable connections without a network switch. For further details, see the Is bonding supported with direct connection using crossover cables? KCS solution.

8.2. Bond modes

In RHEL 8 there are several mode options. Each mode option is characterize by specific load balancing and fault tolerance. The behavior of the bonded interfaces depends upon the mode. The bonding modes provide fault tolerance, load balancing or both.

Load balancing modes

  • Round Robin: Sequentially transmit packets from the first available interface to the last one.

Fault tolerance modes

  • Active Backup: Only when the primary interface fails, one of a backup interfaces replaces it. Only a MAC address used by active interface is visible.
  • Broadcast: All transmissions are sent on all interfaces.

    Note

    Broadcasting significantly increases network traffic on all the bonded interfaces.

Fault tolerance and load balancing modes

  • XOR: The destination MAC addresses are distributed equally between interfaces with a modulo hash. Each interface then serves the same group of MAC addresses.
  • 802.3ad: Sets an IEEE 802.3ad dynamic link aggregation policy. Creates aggregation groups that share the same speed and duplex settings. Transmits and receives on all interfaces in the active aggregator.

    Note

    This mode requires a switch that is 802.3ad compliant.

  • Adaptive transmit load balancing: The outgoing traffic is distributed according to the current load on each interface. Incoming traffic is received by the current interface. If the receiving interface fails, another interface takes over the MAC address of the failed one.
  • Adaptive load balancing: Includes transmit and receive load balancing for IPv4 traffic.

    Receive load balancing is achieved through Address Resolution Protocol (ARP) negotiation, therefore, it is necessary to set Link Monitoring to ARP in the bond’s configuration.

8.3. Adding a new bond using the web console

Configure an active-backup bond on two or more network interfaces using the web console.

Other network bond modes can be configured similarly.

Prerequisites

  • Two or more network cards are installed in the server.
  • The network cards are connected to a switch.

Procedure

  1. Log in to the web console.

    For details, see Logging in to the web console.

  2. Open Networking.
  3. Click the Add Bond button.
  4. In the Bond Settings dialog box, enter a name for the new bond.
  5. In the Members field, select interfaces which should be a member of the bond.
  6. [Optional] In the MAC drop down list, select a MAC address which will be used for this interface.

    If you leave the MAC field empty, the bond will get one of the addresses that are listed in the drop down list.

  7. In the Mode drop down list, select the mode.

    For details, see network bond modes

  8. If you select Active Backup, select the primary interface.

    cockpit bond backup

  9. In the Link Monitoring drop down menu, leave here the MII option.

    Only the adaptive load balancing mode requires to switch this option to ARP.

  10. The Monitoring Interval, Link up delay, and Link down delay fields, which contain values in milliseconds, leave as they are. Change it only for a troubleshooting purpose.
  11. Click Apply.

    cockpit bond add

To verify that the bond works correctly, go to the Networking section and check if the Sending and Receiving columns in the Interfaces table display a network activity.

cockpit bond added

8.4. Adding interfaces to the bond using the web console

Network bonds can include multiple interfaces and you can add or remove any of them at any time.

Learn how to add a network interface to an existing bond.

Prerequisites

Procedure

  1. Log in to the web console.

    For details, see Logging in to the web console.

  2. Open Networking.
  3. In the Interfaces table, click on the bond you want to configure.
  4. In the bond settings screen, scroll down to the table of members (interfaces).
  5. Click the + icon.
  6. Select the interface in the drop down list and click it.

    cockpit bond add interface

The RHEL 8 web console adds the interface to the bond.

8.5. Removing or disabling an interface from the bond using the web console

Network bonds can include multiple interfaces. If you need to change a device, you can remove or disable particular interfaces from the bond, which will work with the rest of the active interfaces.

To stop using an interface included in a bond, you can:

  • Remove the interface from the bond.
  • Disable the interface temporarily. The interface stays a part of the bond, but the bond will not use it until you enable it again.

Prerequisites

Procedure

  1. Log in to the RHEL web console.

    For details, see Logging in to the web console.

  2. Open Networking.
  3. Click the bond you want to configure.
  4. In the bond settings screen, scroll down to the table of ports (interfaces).
  5. Select the interface and and remove or disable it:

    • Click the - icon to remove the interface.
    • Switch the ON/OFF button to Off.

    cockpit bond remove interface

Based on your choice, the web console either removes or disables the interface from the bond and you can see it back in the Networking section as standalone interface.

8.6. Removing or disabling a bond using the web console

Remove or disable a network bond using the web console. If you disable the bond, the interfaces stay in the bond, but the bond will not be used for network traffic.

Prerequisites

  • There is an existing bond in the web console.

Procedure

  1. Log in to the web console.

    For details, see Logging in to the web console.

  2. Open Networking.
  3. Click the bond you want to remove.
  4. In the bond settings screen, you can disable the bond with the ON/OFF button or click the Delete button to remove the bond permanently.

    cockpit bond remove

You can go back to Networking and verify that all the interfaces from the bond are now standalone interfaces.