Configuring Network Bonding in RHEL with the Red Hat System Roles network role

Solution: Use the network role to create an active‑backup bond

On Red Hat Enterprise Linux 8 and later you can declaratively configure a bonding interface with the supported rhel-system-roles.network Ansible role. The role translates a simple variable list into the appropriate nmstate or ifcfg files, ensuring the bond is created consistently across hosts.

How the network role works

The role reads the network_connections variable. Each entry defines a connection type (bond, bridge, ethernet, etc.). For a bond you specify type: bond, the interface name, bond options (like mode=active-backup miimon=100), and IPv4 settings. The role applies the configuration with become: true so it runs with root privileges.

Example playbook

# File: bond0-playbook.yml
- hosts: all
  vars:
    network_connections:
      - name: bond0
        type: bond
        interface_name: bond0
        bond_options: mode=active-backup miimon=100
        ipv4:
          address: 192.168.10.10/24
          gateway: 192.168.10.1
        # optional: define slave interfaces if they are not already present
        # port:
        #   - eth0
        #   - eth1
  roles:
    - rhel-system-roles.network

Run the playbook from your Ansible control node:

ansible-playbook -i  bond0-playbook.yml

You need sufficient privileges to modify network settings; the role uses become: true internally, so the invoking user must be allowed to become root (e.g., via sudo).

Verification

After the playbook finishes, log in to a managed host and check:

• ip link show bond0 – should list bond0 as UP and show the slave interfaces.
• cat /proc/net/bonding/bond0 – confirms the active‑backup mode and the currently active slave.

To catch syntax errors before execution, run:

ansible-playbook --syntax-check bond0-playbook.yml

To preview changes without applying them, use:

ansible-playbook -i  --check bond0-playbook.yml

Limits and common mistakes

• The rhel-system-roles package must be installed on the control node (available in the RHEL Extras repository). Without it the role cannot be found.
• The role only exposes parameters defined in its upstream specification; unsupported bond options (e.g., obscure lacp_rate values) will be ignored or cause a failure.
• Omitting become: true (or relying on become elsewhere) leads to silent failures because the role cannot write network configuration files.
• Forgetting to install the role before running the playbook results in an error like “ERROR! the role 'rhel-system-roles.network' was not found”.
• Network changes can disrupt connectivity; test the playbook first with --check or on a non‑production host.

Rollback

If you need to revert the bond, remove the bond entry from network_connections and re‑run the playbook, or delete the connection manually:

nmcli connection delete bond0

After deletion, verify that bond0 no longer appears in ip link show.