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I am fighting with the WOL settings of my Ubuntu box at the moment. The idea is to have an HTTP/SVN server to sleep while it's unused and wake up when it's accessed. So far, wake-on-LAN works and is activated on startup:

Settings for eth1:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  Not reported
        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: pg
        Wake-on: pg
        Current message level: 0x0000003f (63)
        Link detected: yes

As you can see, I also set the wol p flag ('wake on physical activity'). My assumption was that I could convince the device to wake up not only on magic packets, but on any network access. This, however, seems to be wrong.

What does this flag mean then, and: (How) can I misuse this for my evil plans?

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1 Answer 1

I think your assumption is correct. There are many different events you can configure your device to wake up from. The documentation on ethtool isn't very clear on the p flag unfortunately.

A few questions that could help to analyze the problem: When your machine is shutdown, can you confirm that the network card is still running (LEDs blink) ? Are you trying to wake up your machine from within the same subnet or over a router ? How are you trying to wake it up? Can you use a network sniffer (wireshark) on the same network to confirm that data is actually sent on the subnet?

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Thanks for your answer so far! At the moment, I'm trying to wake up the server from the local subnet; the network card is awake in S3 state and WOL by Magic Packet already works. (In fact, due to a bit of packet redirection it also works through the router.) I have not tested what happens to normal packets when the server is asleep though. --- I wonder if what I meant is actually "pattern match", which I would assume is "unicast" in ethtool, and not supported by my network card. Still the question remains what that 'physical activity' is then. It's not plugging the cable in and out. –  sunside Nov 2 '10 at 1:39
I haven't found anything else about the p flag. It's also strange that in your output it says PHYAD:0. In all other examples I saw this was different from 0. I would first really try to constantly ping the server and see if it wakes up. Check the LEDs to see if the server actually receives the packages. If not, you first have to make sure the packages actually reach it. –  socken23 Nov 2 '10 at 6:29
I can confirm that the packets reach the server; It's blinking like a christmas tree. –  sunside Nov 2 '10 at 14:06

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