Chapter 31. Configuring ethtool offload features

Network interface cards can use the TCP offload engine (TOE) to offload processing certain operations to the network controller to improve the network throughput.

This section describes how to set offload features.

31.1. Offload features supported by NetworkManager

You can set the following ethtool offload features using NetworkManager:

  • ethtool.feature-esp-hw-offload
  • ethtool.feature-esp-tx-csum-hw-offload
  • ethtool.feature-fcoe-mtu
  • ethtool.feature-gro
  • ethtool.feature-gso
  • ethtool.feature-highdma
  • ethtool.feature-hw-tc-offload
  • ethtool.feature-l2-fwd-offload
  • ethtool.feature-loopback
  • ethtool.feature-lro
  • ethtool.feature-ntuple
  • ethtool.feature-rx
  • ethtool.feature-rx-all
  • ethtool.feature-rx-fcs
  • ethtool.feature-rx-gro-hw
  • ethtool.feature-rx-udp_tunnel-port-offload
  • ethtool.feature-rx-vlan-filter
  • ethtool.feature-rx-vlan-stag-filter
  • ethtool.feature-rx-vlan-stag-hw-parse
  • ethtool.feature-rxhash
  • ethtool.feature-rxvlan
  • ethtool.feature-sg
  • ethtool.feature-tls-hw-record
  • ethtool.feature-tls-hw-tx-offload
  • ethtool.feature-tso
  • ethtool.feature-tx
  • ethtool.feature-tx-checksum-fcoe-crc
  • ethtool.feature-tx-checksum-ip-generic
  • ethtool.feature-tx-checksum-ipv4
  • ethtool.feature-tx-checksum-ipv6
  • ethtool.feature-tx-checksum-sctp
  • ethtool.feature-tx-esp-segmentation
  • ethtool.feature-tx-fcoe-segmentation
  • ethtool.feature-tx-gre-csum-segmentation
  • ethtool.feature-tx-gre-segmentation
  • ethtool.feature-tx-gso-partial
  • ethtool.feature-tx-gso-robust
  • ethtool.feature-tx-ipxip4-segmentation
  • ethtool.feature-tx-ipxip6-segmentation
  • ethtool.feature-tx-nocache-copy
  • ethtool.feature-tx-scatter-gather
  • ethtool.feature-tx-scatter-gather-fraglist
  • ethtool.feature-tx-sctp-segmentation
  • ethtool.feature-tx-tcp-ecn-segmentation
  • ethtool.feature-tx-tcp-mangleid-segmentation
  • ethtool.feature-tx-tcp-segmentation
  • ethtool.feature-tx-tcp6-segmentation
  • ethtool.feature-tx-udp-segmentation
  • ethtool.feature-tx-udp_tnl-csum-segmentation
  • ethtool.feature-tx-udp_tnl-segmentation
  • ethtool.feature-tx-vlan-stag-hw-insert
  • ethtool.feature-txvlan

For details about the individual offload features, see the documentation of the ethtool utility and the kernel documentation.

31.2. Configuring an ethtool offload feature using NetworkManager

This section describes how you enable and disable ethtool offload features using NetworkManager, as well as how you remove the setting for a feature from a NetworkManager connection profile.

Procedure

  1. For example, to enable the RX offload feature and disable TX offload in the enp1s0 connection profile, enter: 

    # nmcli con modify enp1s0 ethtool.feature-rx on ethtool.feature-tx off

    This command explicitly enables RX offload and disables TX offload.

  2. To remove the setting of an offload feature that you previously enabled or disabled, set the feature’s parameter to ignore. For example, to remove the configuration for TX offload, enter: 

    # nmcli con modify enp1s0 ethtool.feature-tx ignore

  3. Reactivate the network profile: 

    # nmcli connection up enp1s0

Verification steps

  1. Use the ethtool -k command to display the current offload features of a network device: 

    # ethtool -k network_device

Additional resources

31.3. Using System Roles to set ethtool features

You can use the networking RHEL System Role to configure ethtool features of a NetworkManager connection.

Important

When you run a play that uses the networking RHEL System Role, the System Role overrides an existing connection profile with the same name if the settings do not match the ones specified in the play. Therefore, always specify the whole configuration of the network connection profile in the play, even if, for example the IP configuration, already exists. Otherwise the role resets these values to their defaults.

Depending on whether it already exists, the procedure creates or updates the enp1s0 connection profile with the following settings:

  • A static IPv4 address - 198.51.100.20 with a /24 subnet mask
  • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
  • An IPv4 default gateway - 198.51.100.254
  • An IPv6 default gateway - 2001:db8:1::fffe
  • An IPv4 DNS server - 198.51.100.200
  • An IPv6 DNS server - 2001:db8:1::ffbb
  • A DNS search domain - example.com

  • ethtool features:

    • Generic receive offload (GRO): disabled
    • Generic segmentation offload (GSO): enabled
    • TX Stream Control Transmission Protocol (SCTP) segmentation: disabled

Prerequisites

  • The ansible and rhel-system-roles packages are installed on the control node.
  • If you use a different remote user than root when you run the playbook, this user has appropriate sudo permissions on the managed node.

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 ~/configure-ethernet-device-with-ethtool-features.yml playbook with the following content: 

    ---
- name. Configure an Ethernet connection with ethtool features
  hosts: node.example.com
  become: true
  tasks:
  - include_role:
      name: linux-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
          ethtool:
            feature:
              gro: "no"
              gso: "yes"
              tx_sctp_segmentation: "no"
          state: up

  3. Run the playbook:

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

      # ansible-playbook -u root ~/configure-ethernet-device-with-ethtool-features.yml

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

      # ansible-playbook -u user_name --ask-become-pass ~/configure-ethernet-device-with-ethtool-features.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.

Additional resources

  • For a full list of ethtool features and details about the parameters used in network_connections, and for additional information about the network system role, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file.
  • For details about the ansible-playbook command, see the ansible-playbook(1) man page.