Chapter 5. Configuring Network Connection Settings
Chapter 5. Configuring Network Connection Settings This chapter describes various configurations of the network connection settings and shows how to configure them by using NetworkManager . 5.1. Configuring 802.3 Link Settings You can configure the 802.3 link settings of an Ethernet connection by modifying the following configuration parameters: 802-3-ethernet.auto-negotiate 802-3-ethernet.speed 802-3-ethernet.duplex You can configure the 802.3 link settings to three main modes: Ignore link negotiation Enforce auto-negotiation activation Manually set the speed and duplex link settings Ignoring link negotiation In this case, NetworkManager ignores link configuration for an ethernet connection, keeping the already configuration on the device. To ignore link negotiation, set the following parameters: Important If the auto-negotiate parameter is set to no , but the speed and duplex values are not set, that does not mean that auto-negotiation is disabled. Enforcing auto-negotiation activation In this case, NetworkManager enforces auto-negotiation on a device. To enforce auto-negotiation activation, set the following options: Manually setting the link speed and duplex In this case, you can manually configure the speed and duplex settings on the link. To manually set the speed and duplex link settings, set the aforementioned parameters as follows: Important Make sure to set both the speed and the duplex values, otherwise NetworkManager does not update the link configuration. As a system administrator, you can configure 802.3 link settings using one of the following options: the nmcli tool the nm-connection-editor utility Configuring 802.3 Link Settings with the nmcli Tool Procedure Create a new ethernet connection for the enp1s0 device. Set the 802.3 link setting to a configuration of your choice. For details, see Section 5.1, "Configuring 802.3 Link Settings" For example, to manually set the speed option 100 Mbit/s and duplex to full : Configuring 802.3 Link Settings with nm-connection-editor Procedure Enter nm-connection-editor in a terminal. Select the ethernet connection you want to edit and click the gear wheel icon to move to the editing dialog. See Section 3.4.3, "Common Configuration Options Using nm-connection-editor" for more information. Select the link negotiation of your choice. Ignore : link configuration is skipped (default). Automatic : link auto-negotiation is enforced on the device. Manual : the Speed and Duplex options can be specified to enforce the link negotiation. Figure 5.1. Configure 802.3 link settings using nm-connection-editor
802-3-ethernet.auto-negotiate = no 802-3-ethernet.speed = 0 802-3-ethernet.duplex = NULL 802-3-ethernet.auto-negotiate = yes 802-3-ethernet.speed = 0 802-3-ethernet.duplex = NULL 802-3-ethernet.auto-negotiate = no 802-3-ethernet.speed = [speed in Mbit/s] 802-3-ethernet.duplex = [half |full] nmcli connection add con-name MyEthernet type ethernet ifname enp1s0 802-3-ethernet.auto-negotiate no 802-3-ethernet.speed 100 802-3-ethernet.duplex full