Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

Chapter 11. Configuring network adapter offload settings

To reduce CPU load, certain network adapters use offloading features which move the network processing load to the network interface controller (NIC). For example, with Encapsulating Security Payload (ESP) offload, the NIC performs ESP operations to accelerate IPsec connections and reduce CPU load.

By default, most offloading features in Red Hat Enterprise Linux are enabled. Only disable them in the following cases:

  • Temporarily disable offload features for troubleshooting purposes.
  • Permanently disable offload features when a specific feature negatively impacts your host.

If a performance-related offload feature is not enabled by default in a network driver, you can enable it manually.

11.1. Temporarily setting an offload feature

If you expect that an offload feature causes problems or reduces the performance of your host, you can attempt to narrow down the cause by temporarily enabling or disabling it, depending on its current state.

If you temporarily enable or disable an offload feature, it returns to its previous value on the next reboot.

Prerequisites

  • The network card supports offload features.

Procedure

  1. Display the interface’s available offload features and their current state: 

    # ethtool -k enp1s0
...
esp-hw-offload: on
ntuple-filters: off
rx-vlan-filter: off [fixed]
...
    Copy to Clipboard

    The output depends on the capabilities of the hardware and its driver. Note that you cannot change the state of features that are flagged with [fixed].

  2. Temporarily disable an offload feature: 

    # ethtool -K <interface> <feature> <on|off>
    Copy to Clipboard

    • For example, to temporarily disable IPsec Encapsulating Security Payload (ESP) offload on the enp10s0u1 interface, enter: 

      # ethtool -K enp10s0u1 esp-hw-offload off
      Copy to Clipboard

    • For example, to temporarily enable accelerated Receive Flow Steering (aRFS) filtering on the enp10s0u1 interface, enter: 

      # ethtool -K enp10s0u1 ntuple-filters on
      Copy to Clipboard

Verification

  1. Display the states of the offload features: 

    # ethtool -k enp1s0
...
esp-hw-offload: off
ntuple-filters: on
...
    Copy to Clipboard

  2. Test whether the problem you encountered before changing the offload feature still exists.

    • If the problem no longer exists after changing a specific offload feature:

      1. Contact Red Hat Support and report the problem.
      2. Consider permanently setting the offload feature until a fix is available.

    • If the problem still exists after disabling a specific offload feature:

      1. Reset the setting to its previous state by using the ethtool -K <interface> <feature> <on|off> command.
      2. Enable or disable a different offload feature to narrow down the problem.

11.2. Permanently setting an offload feature

If you have identified a specific offload feature that limits the performance on your host, you can permanently enable or disable it, depending on its current state.

If you permanently enable or disable an offload feature, NetworkManager ensures that the feature still has this state after a reboot.

Prerequisites

  • You identified a specific offload feature to limit the performance on your host.

Procedure

  1. Identify the connection profile that uses the network interface on which you want to change the state of the offload feature: 

    # nmcli connection show
NAME     UUID                                  TYPE      DEVICE
Example  a5eb6490-cc20-3668-81f8-0314a27f3f75  ethernet  enp1ss0
...
    Copy to Clipboard

  2. Permanently change the state of the offload feature: 

    # nmcli connection modify <connection_name> <feature> <on|off>
    Copy to Clipboard

    • For example, to permanently disable IPsec Encapsulating Security Payload (ESP) offload in the Example connection profile, enter: 

      # nmcli connection modify Example ethtool.feature-esp-hw-offload off
      Copy to Clipboard

    • For example, to permanently enable accelerated Receive Flow Steering (aRFS) filtering in the Example connection profile, enter: 

      # nmcli connection modify Example ethtool.feature-ntuple on
      Copy to Clipboard

  3. Reactivate the connection profile: 

    # nmcli connection up Example
    Copy to Clipboard

Verification

  • Display the output states of the offload features: 

    # ethtool -k enp1s0
...
esp-hw-offload: off
ntuple-filters: on
...
    Copy to Clipboard
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat