How Wake on LAN proxy (WOL) works

Products

• Deployment Solution
• Ghost Solution Suite

Issue/Introduction

How Wake on LAN proxy (WOL) works

Resolution

Question

 

How does Wake on LAN proxy work?

 

Answer

 

There are two different types of proxies within Dagent: Wake on LAN and Multicasting. (Note: All proxy communication are using the transport settings that are configured in the Altiris Express Server applet Options > Transport tab.) Wake on LAN packets will go out on the configured port using normal Wake on LAN communication standards.  

To enable an Dagent to act as a Wake on LAN (WOL) proxy, right-click on the client computer in the DS console. Change Agent settings > Production agent. Select the Proxy tab. Also make sure the client connects directly to the Deployment Server via TCP/IP on the Server connection tab. As this machine will be operating as a WOL Proxy for all other agent systems on this subnet, we recommend that you select a static computer that is turned on most of the time.

 

1. The DS/GSS server will send out a WOL packet on UDP port 402 to the broadcast address 255.255.255.255. (See article ,164833 for step-by-step instructions on using Wireshark to troubleshoot WOL issues.)
2. If you are using WOL Proxies on your network (Clients set up as WOL proxies), the server will send a list of all computers that require the WOL packet. 
3. The WOL proxy computer will then send the WOL packet but it may send them out on UDP port 401 instead of port 402.

If you are using WOL Proxies and you have logging turned on the client to log everything, then you will see the MAC addresses of the machines that the WOL proxy will try to wake up.  

The following SQL query will return the number of clients that are acting as WOL Proxies.

SELECT count(*) FROM aclient_prop WHERE wol_proxy = 1

The following SQL query will return the Names and IP addresses of WOL Proxies.

SELECT c.computer_name, d.ip_address
FROM aclient_prop a INNER JOIN
     computer c ON a.computer_id = c.computer_id INNER JOIN
     computer_display d ON a.computer_id = d.computer_id
WHERE a.wol_proxy = 1

Before the server sends a Wake on LAN proxy packet, it will check the database for any clients that are Wake on LAN proxies. The server will then send the proxy packet and tell each Wake on LAN proxy to send a Wake on LAN packet on their segment. Each proxy generates a new Wake on LAN packet for its segment.