Purpose:
You wish to understand how the Wake On LAN feature in PDQ Inventory works, and how to use it.
Resolution:
Prerequisites:
There are three external technical dependencies you will need configured, outside of PDQ Inventory.
- Enable WOL in the BIOS or UEFI of your target computers.
- Enable WOL in the NIC drivers of your target computers.
- Allow WOL broadcasts to traverse your routers.
How it Works:
When you perform a Wake On LAN from PDQ Inventory, it will send the following packets to the target computer(s):
- We send a "General Broadcast" UDP packet to Ports 9, 12287 and 40000.
- The General Broadcast packet is USUALLY blocked by a company's routers. Therefore this packet is generally useful to wake up machines on the same subnet.
- We also send a Directed UDP packet to the subnet of the target on Ports 9, 12287 and 40000.
- We send a Directed UDP packet to the IP Address of the target through Ports 9 and 12287.
- In PDQ Inventory 6 we introduced an additional step to achieve higher success rates with Wake On LAN. Enterprise mode will also attempt to contact a computer in the last known subnet of the target you are waking up. A command will be sent to that last known computer to wake up the target. This should increase the success rates for those environments where Wake On LAN broadcasts (Directed or otherwise) are blocked by your routers.
If PDQ Inventory doesn't have the correct IP Address then you may wake up the wrong system.
The standard Wake On LAN port these days is Port 9. The old standard is Port 12287. Please verify that these ports are opened to allow a "Directed Broadcast".
In order to successfully wake up a computer the MAC Address and the current IP Address of the target computer is required. PDQ Inventory will automatically use the MAC and IP addresses stored in the PDQ Inventory database. If a computer has multiple MAC addresses in the PDQ Inventory database, PDQ Inventory will attempt the Wake On LAN against each MAC address.
You can initiate Wake On LAN by selecting Tools > Wake or by using the shortcut Ctrl+Alt+W.
You can have PDQ Inventory automatically send a Wake on LAN to an offline system before a PDQ Inventory scan is initiated. This can be accomplished via the Offline Policy in Options > Preferences > Scanning > Send Wake-on-LAN and attempt scan. Enterprise Mode is required to use Wake On LAN in the Offline Policy.
