Computers mystically turning themselves on
We use Impero to wake all machines using WOL in the morning which works well but over the last two weeks when machines are shutdown at the end of the day they randomly turn themselves back on usually within 20 minutes.
It is quite a strange problem and still appears even when the Impero server is shutdown so there must be some kind of network chatter somewhere that is causing this.
What is even stranger though is if the machines are set to standby (sleep) then they do not wake up. In the past I have had it the other way around if pattern match was enabled but never this before.
Does anyone have any ideas short of going around and resetting every switch to stop this issue? If the network cable is not attached to a computer then they will not wake but if the cable is attached and the machine is off (not in standby) then they do wake up.
I have checked things like scheduled tasks not causing the PCís to wake up and also checked things like pattern match is disabled but what I donít get if it is WOL then why do they not switch back on if in Standby as Impero still wakes them ok in the morning without any issues.
The other thing is it is not all machines it is around 10% of computers and it is not just one hardware type either.
All running Windows 7 if that helps.
Any suggestions anyone?