Shortening Network Timeouts in Mobile Scenarios

When on the road with their UDC2 mobile device, users often experience slow system startup. This is due to the system waiting for network connections or the UMS which are not available in the mobile scenario. This document describes how to minimize waiting by shortening various timeouts.

Don't Wait for Wired Network

When an Ethernet interface is configured but not physically connected, startup is delayed by default. The goal is to give the user an opportunity to plug in the network cable. If this is not desired, as of IGEL Linux version 5.10.100waiting can be turned off.

1. In Setup, go to System > Registry.

2. Go to the network.interfaces.ethernet.device[number].nolink_nowait registry key. Replace [number] with:

   • 0 for eth0, the first Ethernet interface

   • 1 for eth1, the second Ethernet interface

3. Enable No waiting without physical link. By default, this option is disabled.

Don't Contact UMS Unless Specific Network Devices Are Up

Startup is also delayed because the system tries to contact UMS by default, which may not be available in a mobile scenario. You can configure IGEL Linux version 5.10.100 to contact UMS only if one of the network devices in a whitelist is up.

1. In Setup, go to System > Registry.
2. Go to the system.remotemanager.device_whitelist registry key.
3. Put a space-separated device list into the Network device whitelist field. Only if at least one of these devices is up, the system will try to contact UMS. Device names:
   • First Ethernet adapter: eth0
   • Second Ethernet adapter: eth1
   • Wireless: wlan0

   • Mobile broadband: ppp10

   • OpenVPN: tun0

Don't Contact UMS Unless Specific Networks Are Available

You can configure IGEL Linux version 5.10.100 to contact UMS only if one of the networks in a whitelist is reachable.

1. In Setup, go to System > Registry.
2. Go to the system.remotemanager.network_whitelist registry key.
3. Enter a space-separated list of networks in CIDR notation into the Network whitelist input field, e.g. 172.30.0.0/16 192.168.100.0/24. If there are entries in this field, the system will only try to contact UMS if one of the device's current IP addresses happens to be in one of these ranges.

Shorten the UMS Timeout

When different environments cannot be distinguished by the previous two mechanisms, as of IGEL Linux version 5.10.100 the startup delay can be reduced by setting a shorter timeout for connections to the UMS.

1. In Setup, go to System > Registry.
2. Go to the system.remotemanager.rmagent_timeout registry key.
3. Enter an integer number of seconds into IGEL Remote Management Timeout. The default is 90.

Don't Wait for All Network Interfaces

You can configure IGEL Linux to wait only for one of the network interfaces to be up instead of all. This also means that error messages concerning Ethernet devices will only be displayed shortly.

1. In Setup, go to System > Registry.
2. Go to the network.global.waitfor_interfaces registry key.
3. Disable Wait for interfaces to come up. By default, this option is enabled.