NetworkManager-wait-online.service - Man Page

The NetworkManager-wait-online service is a oneshot systemd service that delays reaching the network-online target until NetworkManager reports that the startup is completed on the D-Bus​.

When the system boots, for example, remote mounts defined in /etc/fstab, require that the network is up​. For this, these systemd units contain the After=network-online​.target setting to order themselves after this target​. NetworkManager-wait-online ensures that the network-online target is reached only after the network is available​.

Optimally, all services on the host react dynamically to network changes and systemd services do not need to be configured to start after reaching the network-online target​. In this case, NetworkManager-wait-online​.service has no effect and does not delay the boot time​. On the other hand, if you encounter a long boot time due to the delay of NetworkManager-wait-online, investigate the services that require network access and fix them​.

Except for the time out value in the NetworkManager-wait-online​.service unit, you cannot configure this service​. Instead, settings in NetworkManager and the connection profiles affect the behavior:

• Startup is not complete as long as NetworkManager profiles are in an activating state​. During boot, NetworkManager starts profiles with the connection​.autoconnect=yes setting​. If activation fails, NetworkManager retries the activation depending on the value of the connection​.autoconnect-retries setting​.

  NetworkManager reports startup complete when all profiles and devices are either activated or in a disconnect state and no further events are expected​.

• When a device reaches the activate state depends on its configuration​. For example, with a profile that has both IPv4 and IPv6 enabled, by default, NetworkManager considers the device as fully activated already when only one of the address families is ready​.

  The ipv4​.may-fail and ipv6​.may-fail settings control this behavior​. Additionally, the following settings influence when the two address families complete: ipv4​.required-timeout, ipv6​.required-timeout, ipv4​.dhcp-timeout, and ipv6​.ra-timeout​. For details, see nm-settings-nmcli(5)​.

• NetworkManager cannot set IP addresses on bridge and bond devices that have ports that do not auto-activate​. Because of this configuration error, NetworkManager-wait-online blocks until the service reaches its timeout value​.
• Dispatcher scripts for the pre-up event run at a late stage during activation of a profile​. These scripts block the activation for when NetworkManager considers the profile fully activated​. For details, see NetworkManager-dispatcher(8)​.
• The property connection​.wait-activation-delay adds an additional delay during activation and delays startup complete​. This setting works around certain cases where a device is known to not be ready for a certain amount of time​.
• The property connection​.wait-device-timeout in the connection profiles cause a delay until the waiting devices appear​. This is useful if the driver takes a longer time to detect the networking interfaces​. This setting is similar to the connection​.gateway-ping-timeout property​.
• With Wi-Fi devices, NetworkManager needs to wait for the first scan result to know which networks are available​. That adds a delay​.
• With Ethernet devices, NetworkManager waits for the carrier until the value in [device*]​.carrier-wait-timeout is reached​. This is because some devices take a long time to detect the carrier​. Consequently, booting with cable unplugged, unnecessarily delays NetworkManager-wait-online​.service​.

Please report any bugs in NetworkManager at the NetworkManager issue tracker​^[1]​.

NetworkManager home page​^[2], NetworkManager(8), nm-online(1), the network-online​.target description in systemd.special(7)

1. NetworkManager issue tracker
   https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues
2. NetworkManager home page
   https://networkmanager.dev

NetworkManager(8), nm-online(1).