Quote Originally Posted by Edders
You could stick the machine's network into a network HUB rather than a switch and have another machine on the same hub running something like Wireshark. If something on the net is sending "wakeup" packets that cause the insomnia to your machine then you should be able to see that.
OK. Everything disconnected (even the IP phones) but my laptop with Ethereal running ... and it seems that the router is waking up the PC:

Code:
No.     Time        Source                Destination           Protocol Info
    101 77.756653   192.168.1.1           Broadcast             ARP      Who has 192.168.1.37?  Tell 192.168.1.1

Frame 101 (60 bytes on wire, 60 bytes captured)
    Arrival Time: Jun 13, 2008 14:25:48.219095000
    Time delta from previous packet: 1.007566000 seconds
    Time since reference or first frame: 77.756653000 seconds
    Frame Number: 101
    Packet Length: 60 bytes
    Capture Length: 60 bytes
    Protocols in frame: eth:arp
Ethernet II, Src: 192.168.1.1 (00:50:7f:b5:c6:c8), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
    Destination: Broadcast (ff:ff:ff:ff:ff:ff)
    Source: 192.168.1.1 (00:50:7f:b5:c6:c8)
    Type: ARP (0x0806)
    Trailer: 000000000000000000000000000000000000
Address Resolution Protocol (request)
    Hardware type: Ethernet (0x0001)
    Protocol type: IP (0x0800)
    Hardware size: 6
    Protocol size: 4
    Opcode: request (0x0001)
    Sender MAC address: 192.168.1.1 (00:50:7f:b5:c6:c8)
    Sender IP address: 192.168.1.1 (192.168.1.1)
    Target MAC address: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Target IP address: 192.168.1.37 (192.168.1.37)
192.168.1.37 is the unstoppable PC, and it seems to be responding to the broadcast message.

Is this something I can stop?

Thks