Wake-on-LAN

A sleeping host answers nothing. Punktfunk remembers the host's network card address — its MAC address — while the host is awake, and sends it a magic packet (the standard Wake-on-LAN datagram) when you later ask to connect.

The Linux, Windows, Apple and Android apps do this by default; nothing to enable in Punktfunk. The work is on the machine: its BIOS/UEFI and network card have to be armed to wake, and that is where Wake-on-LAN usually fails — jump to Arming the machine if that is what you are here for.

How it works

While running, the host advertises itself over mDNS, including mac — the card carrying the IP clients reach it on first, then any other non-loopback cards as fallbacks, at most four. Each app stores those addresses on its saved host record: Linux, Windows and Android refresh them whenever they see the host advertise, the Apple app when you save the host and on every connect. A sleeping host stops advertising, but the client still has the addresses on disk. That ordering is the whole prerequisite:

The client must have seen the host awake at least once, on a network where the host's mDNS advert reached it. Until then no address is known and there is nothing to wake with — the client says so rather than pretending. On every client but the Linux one you can also type the MAC in by hand; see the table below.

The packet goes out of every one of the client's network interfaces — from a socket bound to that interface's own address, aimed at both its subnet broadcast address and 255.255.255.255 — on UDP ports 9 and 7, repeated three times, plus a unicast to the host's last known address. (A sleeping machine has no ARP entry, and an unbound broadcast leaves by the default route only — on a VPN or mesh machine, not the LAN the host sleeps on.)

Neither the advert nor a magic packet is authenticated. A wrong address only makes the wake fail; the host's certificate fingerprint still gates the connection. See Security.

Over Wi-Fi

A host on Wi-Fi wakes from the same packet via WoWLAN (Wake on Wireless LAN): the adapter stays associated to your access point while the machine sleeps, the access point holds broadcast frames for sleeping stations and releases them on the next beacon, and the adapter wakes the machine when one is a magic packet. Punktfunk publishes a Wi-Fi card's address exactly like a wired one, so the client side is unchanged — but the card has to be armed for it, a different switch from the wired one. See Linux (Wi-Fi) and Windows below.

Two things can still stop it, neither visible from Punktfunk:

• Some access points and mesh systems drop or rate-limit broadcast traffic to sleeping stations (often as "multicast enhancement", "broadcast filtering" or IGMP snooping). If wired hosts wake and a Wi-Fi one never does, turn that off first.
• Some laptops and adapters cut power to the Wi-Fi card in deeper sleep states, dropping the association and with it any chance of a wake.

Waking from a client

Auto-wake on connect is a client setting, on by default, in Settings under Session (Client settings); the TV and controller layouts list it among the general settings. A property of the device and the network, so not part of a settings preset.

With auto-wake on, opening a saved host that is not advertising:

1. Fires one magic packet immediately, then dials anyway — missing from mDNS does not mean unreachable; a host reached over a VPN or another subnet never advertises at all.
2. If the dial fails, shows a "Waking…" screen while it re-sends the packet every 6 seconds and watches for the host once a second.
3. Gives up after 90 seconds. The Apple and Android apps, and Punktfunk Console (the controller-driven shell), park there with Try Again and a cancel rather than an error — a cold box that needs another ten seconds is common. The Linux and Windows apps close the wait and tell you the host didn't come online; start the connect again to retry.
4. Reconnects when the host answers. In the Linux, Windows and Android apps, a host that came back on a different DHCP address has its saved record re-pointed at the new one.

With auto-wake off, a connect goes straight through with no packet and no wait — the setting for hosts behind a VPN, which look offline when they are not.

There is also an explicit wake action, independent of auto-wake, on a saved host's own menu. It appears only when that host is offline and an address is known:

Punktfunk Console carries the row too — Wake hosts automatically, in the same settings list the desktop apps write — but its Wake & Connect button is explicit and appears whatever that row says. In the Apple apps the same button appears when you drive them with a controller, but there it follows the auto-wake setting.

The Apple apps also publish a Wake Host action to Shortcuts, so an automation can wake a host without opening the app. On iPhone and iPad it has a ready-made phrase: "Wake ⟨host⟩ with Punktfunk". It fails with a message if that host has no saved address yet.

On Android 17 and later the app needs the local-network permission before it can touch anything on your LAN — discovery, the stream and a wake packet alike. It asks when you open the host list, and shows an explanation with a link to system settings if you decline.

On the Steam Deck

The Decky plugin has no wake button or wake setting of its own. It starts every stream through the client, so the wake is the client's, on exactly the terms above. It follows Wake hosts automatically in the client's own settings (Open Punktfunk → Settings from the same panel) and is a no-op until the client has learned that host's MAC address.

From the command line

punktfunk, the client-side command, has a wake verb. It ships with the Linux punktfunk-client packages and the Windows client; inside the Flatpak it is flatpak run --command=punktfunk io.unom.Punktfunk. See Host CLI for the rest.

punktfunk wake <host-ref> [--wait]

<host-ref> is a saved host's id, name, or address. Without --wait it sends the packet and returns. With --wait it re-sends every 6 seconds and probes the host every second for up to 90 seconds, returning the moment the host answers.

punktfunk launch wakes on its own: if auto-wake is on and it knows an address, it probes the host first and runs the same wake-and-wait when it doesn't answer. You rarely need to chain the two.

Arming the machine

Two things have to be true on the host machine, and Punktfunk changes neither — whether a machine may be woken off the network is your decision.

1. BIOS/UEFI. Turn on the setting called Wake on LAN, Wake on PCIe or similar. Its name and location vary by vendor.
2. The network card. It has to be armed to wake on a magic packet.

Check the host log first

The fastest diagnosis. On Linux, each time the host starts advertising it inspects the card carrying the advertised address and writes one line. A wired card:

Wake-on-LAN armed (magic packet) on host NIC

Wake-on-LAN is NOT armed on this host's NIC — clients cannot wake it from sleep.

A Wi-Fi card, armed through a different mechanism and asked about separately (iw phy … wowlan show, not ethtool):

Wake-on-WLAN armed (magic packet) on host Wi-Fi NIC

Wake-on-WLAN is NOT armed on this host's Wi-Fi NIC — clients cannot wake it from sleep.

The warning line names the interface and the exact command to fix it. The host only reports; it never changes the card's settings, stays silent when it cannot tell (iw/ethtool missing, a driver that doesn't answer, not enough privilege), and says nothing when mDNS adverts are off (PUNKTFUNK_MDNS=0 or --no-mdns) — then no address is published either.

Read the line on the web console's Logs page, or with journalctl --user -u punktfunk-host. See Troubleshooting.

Windows and macOS hosts do not run this check, so there is no log line to look for there.

Linux (wired)

Ask the card what it is doing. Supports Wake-on: is the capability; Wake-on: is the current setting. g means magic packet, d means disabled.

ethtool enp5s0

Arm it:

sudo ethtool -s enp5s0 wol g

On many systems that does not survive a reboot. Re-run ethtool enp5s0 after the next boot, and make it permanent through your distribution's network configuration if it reset.

Linux (Wi-Fi)

ethtool is the wrong tool here — most wireless drivers report Wake-on: d whether or not they are armed, because the trigger lives in the wireless stack. Ask iw, using the phy behind the interface (/sys/class/net/wlan0/phy80211/name, usually phy0):

iw phy phy0 wowlan show

WoWLAN is disabled means no wake. Armed looks like this; the * wake up on magic packet line is the one that matters:

WoWLAN is enabled:
 * wake up on magic packet

Arm it:

sudo iw phy phy0 wowlan enable magic-packet

That setting is per-phy and NetworkManager re-applies its own on every connection, so on a NetworkManager system set it on the connection instead — this survives reboots and reconnects:

sudo nmcli connection modify <connection> 802-11-wireless.wake-on-wlan magic

iw phy phy0 wowlan show reporting command failed: Operation not supported means the driver has no WoWLAN support at all; that adapter cannot be woken over Wi-Fi. Check iw list | grep -A5 "WoWLAN" for what the hardware claims to support.

Windows

Open Device Manager, find the adapter under Network adapters, and open its properties. On the Power Management tab, allow the device to wake the computer; on the Advanced tab, enable the adapter's magic-packet wake property if it has one. Exact wording depends on the driver.

Wi-Fi adapters use the same two tabs. The Advanced property is often called Wake on Magic Packet there too, sometimes Wake on Wireless LAN; many Wi-Fi drivers expose neither, and those cannot be woken over Wi-Fi. powercfg /devicequery wake_armed lists every device currently allowed to wake the machine — if the adapter is not in it, nothing on the network can wake this host.

Limits

• Wired Ethernet is the sure thing; Wi-Fi works when the adapter supports WoWLAN. Punktfunk sends the same packet either way, but whether a sleeping adapter is still listening is the adapter's and the access point's decision — see Over Wi-Fi.
• Connect once while the host is awake, on the same local network, before you rely on waking it. A host only ever added by address, where mDNS never reached the client, has no learned address — the CLI says so, and the apps don't offer the wake action. Typing the MAC in by hand is the way round that everywhere except the Linux app.
• Magic packets are broadcasts. They do not cross subnets, a VPN or a mesh network. Client and host have to share a LAN segment.
• Punktfunk never sleeps or wakes a host on its own. A wake packet goes out because a connect needs it, or because you asked for one — and putting the host back to sleep is likewise an explicit, permission-gated action: see Host power for the other half of the round trip.
• There is no host-side switch. The host publishes its MAC address and warns when its card is not armed. Whether to wake, when, and how long to wait is decided on the client.