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Chapter 20. Configuring network settings by using RHEL system roles

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By using the network RHEL system role, you can automate network-related configuration and management tasks.

20.1. Configuring an Ethernet connection with a static IP address by using the network RHEL system role with an interface name

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure an Ethernet connection with static IP addresses, gateways, and DNS settings, and assign them to a specified interface name.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the servers configuration.
  • The managed nodes use NetworkManager to configure the network.

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: Ethernet connection profile with static IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                interface_name: enp1s0
                type: ethernet
                autoconnect: yes
                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
                state: up

    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

Verification

  • Query the Ansible facts of the managed node and verify the active network settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_default_ipv4": {
                "address": "192.0.2.1",
                "alias": "enp1s0",
                "broadcast": "192.0.2.255",
                "gateway": "192.0.2.254",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "netmask": "255.255.255.0",
                "network": "192.0.2.0",
                "prefix": "24",
                "type": "ether"
            },
            "ansible_default_ipv6": {
                "address": "2001:db8:1::1",
                "gateway": "2001:db8:1::fffe",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "prefix": "64",
                "scope": "global",
                "type": "ether"
            },
            ...
            "ansible_dns": {
                "nameservers": [
                    "192.0.2.1",
                    "2001:db8:1::ffbb"
                ],
                "search": [
                    "example.com"
                ]
            },
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.2. Configuring an Ethernet connection with a static IP address by using the network RHEL system role with a device path

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure an Ethernet connection with static IP addresses, gateways, and DNS settings, and assign them to a device based on its path instead of its name.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the servers configuration.
  • The managed nodes use NetworkManager to configure the network.
  • You know the path of the device. You can display the device path by using the udevadm info /sys/class/net/<device_name> | grep ID_PATH= command.

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: Ethernet connection profile with static IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: example
                match:
                  path:
                    - pci-0000:00:0[1-3].0
                    - &!pci-0000:00:02.0
                type: ethernet
                autoconnect: yes
                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
                state: up

    The settings specified in the example playbook include the following:

    match
    Defines that a condition must be met in order to apply the settings. You can only use this variable with the path option.
    path
    Defines the persistent path of a device. You can set it as a fixed path or an expression. Its value can contain modifiers and wildcards. The example applies the settings to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0.

    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

Verification

  • Query the Ansible facts of the managed node and verify the active network settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_default_ipv4": {
                "address": "192.0.2.1",
                "alias": "enp1s0",
                "broadcast": "192.0.2.255",
                "gateway": "192.0.2.254",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "netmask": "255.255.255.0",
                "network": "192.0.2.0",
                "prefix": "24",
                "type": "ether"
            },
            "ansible_default_ipv6": {
                "address": "2001:db8:1::1",
                "gateway": "2001:db8:1::fffe",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "prefix": "64",
                "scope": "global",
                "type": "ether"
            },
            ...
            "ansible_dns": {
                "nameservers": [
                    "192.0.2.1",
                    "2001:db8:1::ffbb"
                ],
                "search": [
                    "example.com"
                ]
            },
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.3. Configuring an Ethernet connection with a dynamic IP address by using the network RHEL system role with an interface name

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure an Ethernet connection that retrieves its IP addresses, gateways, and DNS settings from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC). With this role you can assign the connection profile to the specified interface name.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the servers configuration.
  • A DHCP server and SLAAC are available in the network.
  • The managed nodes use the NetworkManager service to configure the network.

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: Ethernet connection profile with dynamic IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                interface_name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  dhcp4: yes
                  auto6: yes
                state: up

    The settings specified in the example playbook include the following:

    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.

    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

Verification

  • Query the Ansible facts of the managed node and verify that the interface received IP addresses and DNS settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_default_ipv4": {
                "address": "192.0.2.1",
                "alias": "enp1s0",
                "broadcast": "192.0.2.255",
                "gateway": "192.0.2.254",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "netmask": "255.255.255.0",
                "network": "192.0.2.0",
                "prefix": "24",
                "type": "ether"
            },
            "ansible_default_ipv6": {
                "address": "2001:db8:1::1",
                "gateway": "2001:db8:1::fffe",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "prefix": "64",
                "scope": "global",
                "type": "ether"
            },
            ...
            "ansible_dns": {
                "nameservers": [
                    "192.0.2.1",
                    "2001:db8:1::ffbb"
                ],
                "search": [
                    "example.com"
                ]
            },
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.4. Configuring an Ethernet connection with a dynamic IP address by using the network RHEL system role with a device path

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure an Ethernet connection that retrieves its IP addresses, gateways, and DNS settings from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC). The role can assign the connection profile to a device based on its path instead of an interface name.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the servers configuration.
  • A DHCP server and SLAAC are available in the network.
  • The managed hosts use NetworkManager to configure the network.
  • You know the path of the device. You can display the device path by using the udevadm info /sys/class/net/<device_name> | grep ID_PATH= command.

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: Ethernet connection profile with dynamic IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: example
                match:
                  path:
                    - pci-0000:00:0[1-3].0
                    - &!pci-0000:00:02.0
                type: ethernet
                autoconnect: yes
                ip:
                  dhcp4: yes
                  auto6: yes
                state: up

    The settings specified in the example playbook include the following:

    match: path
    Defines that a condition must be met in order to apply the settings. You can only use this variable with the path option.
    path: <path_and_expressions>
    Defines the persistent path of a device. You can set it as a fixed path or an expression. Its value can contain modifiers and wildcards. The example applies the settings to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0.
    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.

    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

Verification

  • Query the Ansible facts of the managed node and verify that the interface received IP addresses and DNS settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_default_ipv4": {
                "address": "192.0.2.1",
                "alias": "enp1s0",
                "broadcast": "192.0.2.255",
                "gateway": "192.0.2.254",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "netmask": "255.255.255.0",
                "network": "192.0.2.0",
                "prefix": "24",
                "type": "ether"
            },
            "ansible_default_ipv6": {
                "address": "2001:db8:1::1",
                "gateway": "2001:db8:1::fffe",
                "interface": "enp1s0",
                "macaddress": "52:54:00:17:b8:b6",
                "mtu": 1500,
                "prefix": "64",
                "scope": "global",
                "type": "ether"
            },
            ...
            "ansible_dns": {
                "nameservers": [
                    "192.0.2.1",
                    "2001:db8:1::ffbb"
                ],
                "search": [
                    "example.com"
                ]
            },
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.5. Configuring VLAN tagging by using the network RHEL system role

If your network uses Virtual Local Area Networks (VLANs) to separate network traffic into logical networks, create a NetworkManager connection profile to configure VLAN tagging. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure VLAN tagging and, if a connection profile for the VLAN’s parent device does not exists, the role can create it as well.

Note

If the VLAN device requires an IP address, default gateway, and DNS settings, configure them on the VLAN device and not on the parent device.

Prerequisites

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: VLAN connection profile with Ethernet port
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              # Ethernet profile
              - name: enp1s0
                type: ethernet
                interface_name: enp1s0
                autoconnect: yes
                state: up
                ip:
                  dhcp4: no
                  auto6: no
    
              # VLAN profile
              - name: enp1s0.10
                type: vlan
                vlan:
                  id: 10
                ip:
                  dhcp4: yes
                  auto6: yes
                parent: enp1s0
                state: up

    e settings specified in the example playbook include the following:

    type: <profile_type>
    Sets the type of the profile to create. The example playbook creates two connection profiles: One for the parent Ethernet device and one for the VLAN device.
    dhcp4: <value>
    If set to yes, automatic IPv4 address assignment from DHCP, PPP, or similar services is enabled. Disable the IP address configuration on the parent device.
    auto6: <value>
    If set to yes, IPv6 auto-configuration is enabled. In this case, by default, NetworkManager uses Router Advertisements and, if the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server. Disable the IP address configuration on the parent device.
    parent: <parent_device>
    Sets the parent device of the VLAN connection profile. In the example, the parent is the Ethernet interface.

    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

Verification

  • Verify the VLAN settings:

    # ansible managed-node-01.example.com -m command -a 'ip -d addr show enp1s0.10'
    managed-node-01.example.com | CHANGED | rc=0 >>
    4: vlan10@enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
        link/ether 52:54:00:72:2f:6e brd ff:ff:ff:ff:ff:ff promiscuity 0
        vlan protocol 802.1Q id 10 <REORDER_HDR> numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
        ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.6. Configuring a network bridge by using the network RHEL system role

You can connect multiple networks on layer 2 of the Open Systems Interconnection (OSI) model by creating a network bridge. To configure a bridge, create a connection profile in NetworkManager. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure a bridge and, if a connection profile for the bridge’s parent device does not exists, the role can create it as well.

Note

If you want to assign IP addresses, gateways, and DNS settings to a bridge, configure them on the bridge and not on its ports.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • Two or more physical or virtual network devices are installed on the server.

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: Bridge connection profile with two Ethernet ports
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              # Bridge profile
              - name: bridge0
                type: bridge
                interface_name: bridge0
                ip:
                  dhcp4: yes
                  auto6: yes
                state: up
    
              # Port profile for the 1st Ethernet device
              - name: bridge0-port1
                interface_name: enp7s0
                type: ethernet
                controller: bridge0
                port_type: bridge
                state: up
    
              # Port profile for the 2nd Ethernet device
              - name: bridge0-port2
                interface_name: enp8s0
                type: ethernet
                controller: bridge0
                port_type: bridge
                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 bridge 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.

    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

Verification

  1. Display the link status of Ethernet devices that are ports of a specific bridge:

    # ansible managed-node-01.example.com -m command -a 'ip link show master bridge0'
    managed-node-01.example.com | CHANGED | rc=0 >>
    3: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bridge0 state UP mode DEFAULT group default qlen 1000
        link/ether 52:54:00:62:61:0e brd ff:ff:ff:ff:ff:ff
    4: enp8s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bridge0 state UP mode DEFAULT group default qlen 1000
        link/ether 52:54:00:9e:f1:ce brd ff:ff:ff:ff:ff:ff
  2. Display the status of Ethernet devices that are ports of any bridge device:

    # ansible managed-node-01.example.com -m command -a 'bridge link show'
    managed-node-01.example.com | CHANGED | rc=0 >>
    3: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master bridge0 state forwarding priority 32 cost 100
    4: enp8s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master bridge0 state listening priority 32 cost 100

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.7. Configuring a network bond by using the network RHEL system role

You can combine network interfaces in a bond to provide a logical interface with higher throughput or redundancy. To configure a bond, create a NetworkManager connection profile. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure a network bond and, if a connection profile for the bond’s parent device does not exist, the role can create it as well.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • Two or more physical or virtual network devices are installed on the server.

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: 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

Verification

  • Temporarily remove the network cable from one of the network devices and check if the other device in the bond 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.8. Configuring an IPoIB connection by using the network RHEL system role

You can use IP over InfiniBand (IPoIB) to send IP packets over an InfiniBand interface. To configure IPoIB, create a NetworkManager connection profile. By using Ansible and the network system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure IPoIB and, if a connection profile for the InfiniBand’s parent device does not exists, the role can create it as well.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • An InfiniBand device named mlx4_ib0 is installed in the managed nodes.
  • The managed nodes use NetworkManager to configure the network.

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: IPoIB connection profile with static IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              # InfiniBand connection mlx4_ib0
              - name: mlx4_ib0
                interface_name: mlx4_ib0
                type: infiniband
    
              # IPoIB device mlx4_ib0.8002 on top of mlx4_ib0
              - name: mlx4_ib0.8002
                type: infiniband
                autoconnect: yes
                infiniband:
                  p_key: 0x8002
                  transport_mode: datagram
                parent: mlx4_ib0
                ip:
                  address:
                    - 192.0.2.1/24
                    - 2001:db8:1::1/64
                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 two connection profiles: One for the InfiniBand connection and one for the IPoIB device.
    parent: <parent_device>
    Sets the parent device of the IPoIB connection profile.
    p_key: <value>
    Sets the InfiniBand partition key. If you set this variable, do not set interface_name on the IPoIB device.
    transport_mode: <mode>
    Sets the IPoIB connection operation mode. You can set this variable to datagram (default) or connected.

    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

Verification

  1. Display the IP settings of the mlx4_ib0.8002 device:

    # ansible managed-node-01.example.com -m command -a 'ip address show mlx4_ib0.8002'
    managed-node-01.example.com | CHANGED | rc=0 >>
    ...
    inet 192.0.2.1/24 brd 192.0.2.255 scope global noprefixroute ib0.8002
       valid_lft forever preferred_lft forever
    inet6 2001:db8:1::1/64 scope link tentative noprefixroute
       valid_lft forever preferred_lft forever
  2. Display the partition key (P_Key) of the mlx4_ib0.8002 device:

    # ansible managed-node-01.example.com -m command -a 'cat /sys/class/net/mlx4_ib0.8002/pkey'
    managed-node-01.example.com | CHANGED | rc=0 >>
    0x8002
  3. Display the mode of the mlx4_ib0.8002 device:

    # ansible managed-node-01.example.com -m command -a 'cat /sys/class/net/mlx4_ib0.8002/mode'
    managed-node-01.example.com | CHANGED | rc=0 >>
    datagram

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.9. Routing traffic from a specific subnet to a different default gateway by using the network RHEL system role

You can use policy-based routing to configure a different default gateway for traffic from certain subnets. For example, you can configure RHEL as a router that, by default, routes all traffic to internet provider A using the default route. However, traffic received from the internal workstations subnet is routed to provider B. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use the network RHEL system role to configure the connection profiles, including routing tables and rules.

This procedure assumes the following network topology:

policy based routing

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes uses the NetworkManager and firewalld services.
  • The managed nodes you want to configure has four network interfaces:

    • The enp7s0 interface is connected to the network of provider A. The gateway IP in the provider’s network is 198.51.100.2, and the network uses a /30 network mask.
    • The enp1s0 interface is connected to the network of provider B. The gateway IP in the provider’s network is 192.0.2.2, and the network uses a /30 network mask.
    • The enp8s0 interface is connected to the 10.0.0.0/24 subnet with internal workstations.
    • The enp9s0 interface is connected to the 203.0.113.0/24 subnet with the company’s servers.
  • Hosts in the internal workstations subnet use 10.0.0.1 as the default gateway. In the procedure, you assign this IP address to the enp8s0 network interface of the router.
  • Hosts in the server subnet use 203.0.113.1 as the default gateway. In the procedure, you assign this IP address to the enp9s0 network interface of the router.

Procedure

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

    ---
    - name: Configuring policy-based routing
      hosts: managed-node-01.example.com
      tasks:
        - name: Routing traffic from a specific subnet to a different default gateway
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: Provider-A
                interface_name: enp7s0
                type: ethernet
                autoconnect: True
                ip:
                  address:
                    - 198.51.100.1/30
                  gateway4: 198.51.100.2
                  dns:
                    - 198.51.100.200
                state: up
                zone: external
    
              - name: Provider-B
                interface_name: enp1s0
                type: ethernet
                autoconnect: True
                ip:
                  address:
                    - 192.0.2.1/30
                  route:
                    - network: 0.0.0.0
                      prefix: 0
                      gateway: 192.0.2.2
                      table: 5000
                state: up
                zone: external
    
              - name: Internal-Workstations
                interface_name: enp8s0
                type: ethernet
                autoconnect: True
                ip:
                  address:
                    - 10.0.0.1/24
                  route:
                    - network: 10.0.0.0
                      prefix: 24
                      table: 5000
                  routing_rule:
                    - priority: 5
                      from: 10.0.0.0/24
                      table: 5000
                state: up
                zone: trusted
    
              - name: Servers
                interface_name: enp9s0
                type: ethernet
                autoconnect: True
                ip:
                  address:
                    - 203.0.113.1/24
                state: up
                zone: trusted

    The settings specified in the example playbook include the following:

    table: <value>
    Assigns the route from the same list entry as the table variable to the specified routing table.
    routing_rule: <list>
    Defines the priority of the specified routing rule and from a connection profile to which routing table the rule is assigned.
    zone: <zone_name>
    Assigns the network interface from a connection profile to the specified firewalld zone.

    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

Verification

  1. On a RHEL host in the internal workstation subnet:

    1. Install the traceroute package:

      # yum install traceroute
    2. Use the traceroute utility to display the route to a host on the internet:

      # traceroute redhat.com
      traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
       1  10.0.0.1 (10.0.0.1)     0.337 ms  0.260 ms  0.223 ms
       2  192.0.2.1 (192.0.2.1)   0.884 ms  1.066 ms  1.248 ms
       ...

      The output of the command displays that the router sends packets over 192.0.2.1, which is the network of provider B.

  2. On a RHEL host in the server subnet:

    1. Install the traceroute package:

      # yum install traceroute
    2. Use the traceroute utility to display the route to a host on the internet:

      # traceroute redhat.com
      traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
       1  203.0.113.1 (203.0.113.1)    2.179 ms  2.073 ms  1.944 ms
       2  198.51.100.2 (198.51.100.2)  1.868 ms  1.798 ms  1.549 ms
       ...

      The output of the command displays that the router sends packets over 198.51.100.2, which is the network of provider A.

  3. On the RHEL router that you configured using the RHEL system role:

    1. Display the rule list:

      # ip rule list
      0:      from all lookup local
      5:    from 10.0.0.0/24 lookup 5000
      32766:  from all lookup main
      32767:  from all lookup default

      By default, RHEL contains rules for the tables local, main, and default.

    2. Display the routes in table 5000:

      # ip route list table 5000
      0.0.0.0/0 via 192.0.2.2 dev enp1s0 proto static metric 100
      10.0.0.0/24 dev enp8s0 proto static scope link src 192.0.2.1 metric 102
    3. Display the interfaces and firewall zones:

      # firewall-cmd --get-active-zones
      external
        interfaces: enp1s0 enp7s0
      trusted
        interfaces: enp8s0 enp9s0
    4. Verify that the external zone has masquerading enabled:

      # firewall-cmd --info-zone=external
      external (active)
        target: default
        icmp-block-inversion: no
        interfaces: enp1s0 enp7s0
        sources:
        services: ssh
        ports:
        protocols:
        masquerade: yes
        ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.10. Configuring a static Ethernet connection with 802.1X network authentication by using the network RHEL system role

Network Access Control (NAC) protects a network from unauthorized clients. You can specify the details that are required for the authentication in NetworkManager connection profiles to enable clients to access the network. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

You can use an Ansible playbook to copy a private key, a certificate, and the CA certificate to the client, and then use the network RHEL system role to configure a connection profile with 802.1X network authentication.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The network supports 802.1X network authentication.
  • The managed nodes use NetworkManager.
  • The following files required for the TLS authentication exist on the control node:

    • The client key is stored in the /srv/data/client.key file.
    • The client certificate is stored in the /srv/data/client.crt file.
    • The Certificate Authority (CA) certificate is stored in the /srv/data/ca.crt file.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <vault_password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      pwd: <password>
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  2. Create a playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Configure an Ethernet connection with 802.1X authentication
      hosts: managed-node-01.example.com
      vars_files:
        - vault.yml
      tasks:
        - name: Copy client key for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/client.key"
            dest: "/etc/pki/tls/private/client.key"
            mode: 0600
    
        - name: Copy client certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/client.crt"
            dest: "/etc/pki/tls/certs/client.crt"
    
        - name: Copy CA certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/ca.crt"
            dest: "/etc/pki/ca-trust/source/anchors/ca.crt"
    
        - name: Ethernet connection profile with static IP address settings and 802.1X
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                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
                ieee802_1x:
                  identity: <user_name>
                  eap: tls
                  private_key: "/etc/pki/tls/private/client.key"
                  private_key_password: "{{ pwd }}"
                  client_cert: "/etc/pki/tls/certs/client.crt"
                  ca_cert: "/etc/pki/ca-trust/source/anchors/ca.crt"
                  domain_suffix_match: example.com
                state: up

    The settings specified in the example playbook include the following:

    ieee802_1x
    This variable contains the 802.1X-related settings.
    eap: tls
    Configures the profile to use the certificate-based TLS authentication method for the Extensible Authentication Protocol (EAP).

    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.

  3. Validate the playbook syntax:

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Verification

  • Access resources on the network that require network authentication.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory
  • Ansible vault

20.11. Setting the default gateway on an existing connection by using the network RHEL system role

A host forwards a network packet to its default gateway if the packet’s destination can neither be reached through the directly-connected networks nor through any of the routes configured on the host. To configure the default gateway of a host, set it in the NetworkManager connection profile of the interface that is connected to the same network as the default gateway. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

In most situations, administrators set the default gateway when they create a connection. However, you can also set or update the default gateway setting on a previously-created connection.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

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: Ethernet connection profile with static IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  address:
                    - 198.51.100.20/24
                    - 2001:db8:1::1/64
                  gateway4: 198.51.100.254
                  gateway6: 2001:db8:1::fffe
                  dns:
                    - 198.51.100.200
                    - 2001:db8:1::ffbb
                  dns_search:
                    - example.com
                state: up

    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

Verification

  • Query the Ansible facts of the managed node and verify the active network settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_default_ipv4": {
    	    ...
                "gateway": "198.51.100.254",
                "interface": "enp1s0",
    	    ...
            },
            "ansible_default_ipv6": {
    	    ...
                "gateway": "2001:db8:1::fffe",
                "interface": "enp1s0",
    	    ...
    	}
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.12. Configuring a static route by using the network RHEL system role

A static route ensures that you can send traffic to a destination that cannot be reached through the default gateway. You configure static routes in the NetworkManager connection profile of the interface that is connected to the same network as the next hop. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

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: Ethernet connection profile with static IP address settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp7s0
                type: ethernet
                autoconnect: yes
                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
                  route:
                    - network: 198.51.100.0
                      prefix: 24
                      gateway: 192.0.2.10
                    - network: 2001:db8:2::
                      prefix: 64
                      gateway: 2001:db8:1::10
                state: up

    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

Verification

  1. Display the IPv4 routes:

    # ansible managed-node-01.example.com -m command -a 'ip -4 route'
    managed-node-01.example.com | CHANGED | rc=0 >>
    ...
    198.51.100.0/24 via 192.0.2.10 dev enp7s0
  2. Display the IPv6 routes:

    # ansible managed-node-01.example.com -m command -a 'ip -6 route'
    managed-node-01.example.com | CHANGED | rc=0 >>
    ...
    2001:db8:2::/64 via 2001:db8:1::10 dev enp7s0 metric 1024 pref medium

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.13. Configuring an ethtool offload feature by using the network RHEL system role

Network interface controllers can use the TCP offload engine (TOE) to offload processing certain operations to the network controller. This improves the network throughput. You configure offload features in the connection profile of the network interface. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

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: Ethernet connection profile with dynamic IP address settings and offload features
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  dhcp4: yes
                  auto6: yes
                ethtool:
                  features:
                    gro: no
                    gso: yes
                    tx_sctp_segmentation: no
                state: up

    The settings specified in the example playbook include the following:

    gro: no
    Disables Generic receive offload (GRO).
    gso: yes
    Enables Generic segmentation offload (GSO).
    tx_sctp_segmentation: no
    Disables TX stream control transmission protocol (SCTP) segmentation.

    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

Verification

  • Query the Ansible facts of the managed node and verify the offload settings:

    # ansible managed-node-01.example.com -m ansible.builtin.setup
    ...
            "ansible_enp1s0": {
                "active": true,
                "device": "enp1s0",
    	    "features": {
    	        ...
    		"rx_gro_hw": "off,
    	        ...
    		"tx_gso_list": "on,
    	        ...
    		"tx_sctp_segmentation": "off",
    		...
                }
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.14. Configuring an ethtool coalesce settings by using the network RHEL system role

By using interrupt coalescing, the system collects network packets and generates a single interrupt for multiple packets. This increases the amount of data sent to the kernel with one hardware interrupt, which reduces the interrupt load, and maximizes the throughput. You configure coalesce settings in the connection profile of the network interface. By using Ansible and the network RHEL role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

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: Ethernet connection profile with dynamic IP address settings and coalesce settings
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  dhcp4: yes
                  auto6: yes
                ethtool:
                  coalesce:
                    rx_frames: 128
                    tx_frames: 128
                state: up

    The settings specified in the example playbook include the following:

    rx_frames: <value>
    Sets the number of RX frames.
    gso: <value>
    Sets the number of TX frames.

    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

Verification

  • Display the current offload features of the network device:

    # ansible managed-node-01.example.com -m command -a 'ethtool -c enp1s0'
    managed-node-01.example.com | CHANGED | rc=0 >>
    ...
    rx-frames:	128
    ...
    tx-frames:	128
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.15. Increasing the ring buffer size to reduce a high packet drop rate by using the network RHEL system role

Increase the size of an Ethernet device’s ring buffers if the packet drop rate causes applications to report a loss of data, timeouts, or other issues.

Ring buffers are circular buffers where an overflow overwrites existing data. The network card assigns a transmit (TX) and receive (RX) ring buffer. Receive ring buffers are shared between the device driver and the network interface controller (NIC). Data can move from NIC to the kernel through either hardware interrupts or software interrupts, also called SoftIRQs.

The kernel uses the RX ring buffer to store incoming packets until the device driver can process them. The device driver drains the RX ring, typically by using SoftIRQs, which puts the incoming packets into a kernel data structure called an sk_buff or skb to begin its journey through the kernel and up to the application that owns the relevant socket.

The kernel uses the TX ring buffer to hold outgoing packets which should be sent to the network. These ring buffers reside at the bottom of the stack and are a crucial point at which packet drop can occur, which in turn will adversely affect network performance.

You configure ring buffer settings in the NetworkManager connection profiles. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You know the maximum ring buffer sizes that the device supports.

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: Ethernet connection profile with dynamic IP address setting and increased ring buffer sizes
          ansible.builtin.include_role:
            name: rhel-system-roles.network
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  dhcp4: yes
                  auto6: yes
                ethtool:
                  ring:
                    rx: 4096
                    tx: 4096
                state: up

    The settings specified in the example playbook include the following:

    rx: <value>
    Sets the maximum number of received ring buffer entries.
    tx: <value>
    Sets the maximum number of transmitted ring buffer entries.

    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

Verification

  • Display the maximum ring buffer sizes:

    # ansible managed-node-01.example.com -m command -a 'ethtool -g enp1s0'
    managed-node-01.example.com | CHANGED | rc=0 >>
    ...
    Current hardware settings:
    RX:             4096
    RX Mini:        0
    RX Jumbo:       0
    TX:             4096

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory

20.16. Network states for the network RHEL system role

The network RHEL system role supports state configurations in playbooks to configure the devices. For this, use the network_state variable followed by the state configurations.

Benefits of using the network_state variable in a playbook:

  • Using the declarative method with the state configurations, you can configure interfaces, and the NetworkManager creates a profile for these interfaces in the background.
  • With the network_state variable, you can specify the options that you require to change, and all the other options will remain the same as they are. However, with the network_connections variable, you must specify all settings to change the network connection profile.

For example, to create an Ethernet connection with dynamic IP address settings, use the following vars block in your playbook:

Playbook with state configurations

Regular playbook

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: up
      ipv4:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        dhcp: true
      ipv6:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        autoconf: true
        dhcp: true
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: up

For example, to only change the connection status of dynamic IP address settings that you created as above, use the following vars block in your playbook:

Playbook with state configurations

Regular playbook

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: down
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: down

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file
  • /usr/share/doc/rhel-system-roles/network/ directory
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