Selection

Desomnia can be configured to monitor one or more network interfaces installed in your system. Upon service startup and every time your network configuration changes, the configurations of all connected interfaces are compared against your <NetworkMonitor> configurations. There are several ways to control which configuration applies to which interface:

Automatic selection

<NetworkMonitor>
    <!-- hosts, etc. -->
</NetworkMonitor>

If you specify neither interface nor network, Desomnia monitors all interfaces that have a standard gateway configured. This is typically the interface connected to your local network. If multiple interfaces with a gateway are present — for example, an active wired and wireless connection to the same network — all of them will be monitored using this single configuration, which may be exactly what you want in that situation.

By network

<NetworkMonitor network="192.168.178.0/24">
    <!-- hosts, etc. -->
</NetworkMonitor>

When you specify a network in CIDR notation, the <NetworkMonitor> is activated only for interfaces that have joined that particular network, as determined by the interface’s IP address and prefix length. This applies to both IPv4 and IPv6 networks. You can also use a single concrete IP address to bind to a specific link.

By interface name

<NetworkMonitor interface="eth0">
    <!-- hosts, etc. -->
</NetworkMonitor>

When you specify an interface name, the <NetworkMonitor> is activated only for interfaces with a matching name. On Linux and macOS, the value is a case-sensitive regular expression matched against the interface name. On Windows, it is a regular expression matched against the adapter GUID, or an exact match for the human-readable adapter name. A regular expression such as Ethernet.* does not match Windows display names. How interfaces are identified differs between operating systems:

Windows

OS:

🪟

On Windows, every network interface is assigned a unique GUID and a human-readable name. The name can be changed in the system settings, but the GUID always remains the same. You can query both using PowerShell:

Get-NetAdapter | Select-Object Name, InterfaceDescription, InterfaceGuid

Name                         InterfaceDescription                                      InterfaceGuid
----                         --------------------                                      -------------
Bluetooth-Netzwerkverbindung Bluetooth Device (Personal Area Network)                  {6912B25F-0702-4ACC-AB22-82B3157A89FB}
Netzwerkbrücke               Hyper-V Virtual Ethernet Adapter                          {5334C77C-2E13-4005-A7CE-C6889A312B5F}
WLAN                         MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz Wireless LAN Card {44ECA482-24F2-4362-99F8-88A17A450B45}
Ethernet                     Intel(R) Ethernet Controller (3) I225-V                   {1BD73899-523C-4911-967A-FE797ACF6C44}

To match by name, use the exact string shown in the Name column. To match by GUID, the curly braces are optional.

Linux and macOS

OS:

🐧 🍎

On Linux and macOS, interfaces are identified by their device name — typically something like eth0, eth1, en0, or wlan0, depending on the OS, distribution, and number of installed interfaces.

To list all interfaces and their names, use ip link show on Linux:

ip link show

On older systems or macOS, ifconfig shows the same information:

ifconfig

By interface name and network

<NetworkMonitor interface="eth0" network="192.168.178.20">
    <!-- hosts, etc. -->
</NetworkMonitor>

You can combine both attributes to activate a configuration only when a specific interface has joined a specific network. If multiple configurations match the same interface, the first matching one in the configuration file is used. Each interface is monitored at most once.

Exact matches and regular expressions

Regular expressions are not automatically anchored. On Linux/macOS, interface="^en0$" selects exactly en0, while interface="en0|en5" can match either name. Escape regex metacharacters when they are meant literally. On Windows, use the exact displayed adapter name or a pattern matching its GUID.

The same selectors are used for interface configuration and environment conditions. Environment conditions additionally allow an operational-status suffix; do not add that suffix to a network monitor’s interface selector.

Hot plugging

You can add, remove, connect, or disconnect network interfaces at runtime without restarting Desomnia.