Wednesday, August 10, 2011

Troubleshooting Wake On LAN (WOL) in ConfigMgr

In my other blog about Wake On LAN (WOL): I explained which functionality becomes available in ConfigMgr 2007/2012. This can be used to schedule OS deployment, Software distribution and Patch management during non-working hours to wake-up devices. But what to do when it isn't working and you don't know what to do next? In this blog I will explain my best practices from the field, and how WOL will be functional (again).

Most of times using Unicast is the easiest one to configure. Then devices in the same subnet can be used for WOL functionality only. In the field however there are most of times different subnets for servers and clients. Then "Subnet-directed broadcasts" is the best way for configure WOL functionality. More about that in my other blog: "Wake On LAN (WOL) functionality in ConfigMgr".

First something about Site boundaries here. In ConfigMgr it's possible to create Site boundaries with IP-subnets, AD-sites and IP-address ranges. They all seems okay, but because ConfigMgr cannot handle supernetting, IP-address ranges is the only right choice here! A supernet is an Internet Protocol (IP) network that is formed from the combination of two or more networks (or subnets). WIKI page:

Because supernetting can be used in both IP-subnets and AD-sites, they are not the best choice for implementing Wake On LAN functionality. There's also a nice TechNet blog available about that: Known Issue: Supernets in Active Directory Sites Used as Site Boundaries:

(after creating an IP-subnet, only the Subnet ID remains visible) 

(with IP-address ranges, the complete range remains visible) 

Now the best practices from the field, based on above suggestions: 
  • Remove any existing Site Boundaries based on both IP-subnets and AD-sites (write down there IP-address ranges, but don't use them anymore)
  • Create IP-address ranges based on formerly existing Site boundaries (only use complete ranges from 1-255 to get Wake On LAN working)
  • In Site properties > select "Use wake-up packets only" and "Subnet-directed broadcasts" (Power on commands are used only with Out of Band Management)
  • In Site properties > the UDP port can remains on port 9 (default), when there are issues with that use port 12287
  • Create a new advertisement now, and set an mandatory assignment on that (otherwise there is no WOL functionality possible)
After this WOL functionality must be available on "Subnet-directed broadcasts". Remember that WOL functionality is only available on OS deployment, Software distribution and Patch management in combination with an mandatory assignment. Good luck!

No comments:

Post a Comment