Wake-on-LAN - Lenovo ThinkPad T430 (orchestration host)¶

The Wake-on-LAN setup allows to power on the orchestration host remotely if it is off. WoL lets testbed admins power the lab from outside without physical access.

Context: If powered-off, the host does not receive ZeroTier traffic. The WoL packet must be sent from an always-on device on the same LAN (the OpenWrt gateway router, which runs ZeroTier). See gateway 5.8 for the full remote flow.

1. Prerequisites¶

Active Ethernet interface (on our T430 host: enp0s25).
Ethernet cable to switch/gateway (same VLAN/LAN as the orchestration host).

2. BIOS - Enable Wake-on-LAN¶

BIOS must allow WoL. On ThinkPad T430:

2.1 Enter BIOS¶

Reboot the laptop.
When the ThinkPad logo appears, press F1.
BIOS Setup Utility opens.

2.2 Enable Wake-on-LAN¶

Navigate to: Config > Network > Wake On Lan

Set Wake on LAN = AC Only (AC power only).

Save and exit.

3. Linux - ethtool (after boot)¶

After Ubuntu boots, enable WoL on the Ethernet interface.

3.1 Check interface and state¶

ip link show
# Identify Ethernet (on T430: enp0s25)

sudo ethtool enp0s25

In the output, find Wake-on:. If it shows d (disabled), enable it.

3.2 Enable WoL¶

sudo ethtool -s enp0s25 wol g

g = magic packet (standard WoL). After this, ethtool enp0s25 should show Wake-on: g.

3.3 Behavior after reboot¶

WoL persistence

Without extra configuration, the setting is lost on reboot. Use the systemd persistence service (section 4) or the Ansible role (section 5).

4. Persistence - systemd service (manual)¶

To keep WoL enabled after each boot, use a systemd unit that runs ethtool at startup.

4.1 Create the service¶

sudo nano /etc/systemd/system/wol.service

Content (adjust enp0s25 if the Ethernet name differs):

[Unit]
Description=Enable Wake On LAN
After=NetworkManager.service
Wants=NetworkManager.service

[Service]
Type=oneshot
ExecStartPre=/bin/sleep 5
ExecStart=/usr/sbin/ethtool -s enp0s25 wol g
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

Order vs NetworkManager

The service must run after NetworkManager. With After=network.target, NM may reset Wake-on to d after the service sets g. ExecStartPre=sleep 5 gives NM time to finish.

4.2 Enable the service¶

sudo systemctl daemon-reload
sudo systemctl enable wol
sudo systemctl start wol

On each reboot, the service enables WoL automatically.

4.3 Verification¶

sudo systemctl status wol
sudo ethtool enp0s25
# Should show Wake-on: g

5. Automation with Ansible¶

The Ansible wol role creates and enables the systemd service idempotently. See host-config 8.4.

Run:

ansible-playbook -i ansible/inventory/hosts.yml ansible/playbook_testbed.yml --tags wol -K

6. Get the host MAC¶

To send the magic packet from the gateway (or another LAN host), you need the Lenovo MAC.

ip link show enp0s25
# Find "link/ether XX:XX:XX:XX:XX:XX"

Or:

cat /sys/class/net/enp0s25/address

Store that MAC (e.g. as LABGRID_HOST_MAC in gateway docs) for wakeonlan or equivalents.

7. Send WoL (from gateway or LAN)¶

The magic packet must come from a device on the same subnet as the Lenovo (or broadcast). The gateway router (always on) is the natural sender when accessing remotely via ZeroTier.

7.1 OpenWrt (current setup: TL-WDR3500)¶

Testbed gateway is OpenWrt with etherwake installed and ZeroTier for remote access. Send WoL on a testbed VLAN:

ssh root@<ZeroTier-IP-of-router> 'etherwake -i eth0.100 00:21:cc:c4:25:3b'

See gateway 5.8 for full router configuration.

7.2 MikroTik (deprecated - previous setup)¶

If a MikroTik were used again as testbed gateway:

/tool wol mac=00:21:CC:C4:25:3B interface=LAB-TRUNK

7.3 Via ZeroTier (full flow)¶

SSH to OpenWrt router via ZeroTier: ssh root@10.246.3.95
Send WoL: etherwake -i eth0.100 00:21:cc:c4:25:3b
Wait ~2 min for the Lenovo to boot.
SSH to host via ZeroTier: ssh laryc@10.246.3.118