WAKE ON LAN - Setup help please....

[myT40xxx999]

Hi,

I have a T40 with Intel(R) PRO/1000 MT Mobile Connection NIC and I am trying to get WOL to work.

So Far;

I have checked that WOL is enabled in the BIOS.

I have gone to device manager and for the NIC advanced setting have enabled; Enable PME & Wake On Magic Packet.

I set my adsl router to allow port 7 (UDP) straight through to my laptop.
I have installed Magic Packets and entered the MAC address & IP details and used port 7.

When I send the MP nothing happens.

I note the link/activity lights on the T40 do not light up at all when the laptop is switched off.

Can anyone please help?

[EOMtp]

WOL (Wake On LAN) will not work if your machine is connected through a router or switch, because the router's/switch's ARP table will be purged -- i.e., the router/switch will "forget" the MAC address of your machine's Ethernet port -- within 5-10 minutes of turning off your machine (depends on the particular router/switch hardware).

There is no workaround if the machine to be awakened is connected to a switch which purges periodically its ARP table of inactive MACs. The only "solution" -- although probably not a practical one -- is for your machine to be connected directly to the Internet, i.e., for your machine to have a routable IP address and not be connected through a switch.

[myT40xxx999]

Hi,

I'm no network expert, but doesn't the subnet on a router take care of that? At work the IT guys do WOL on servers connected to switches?

I've also just tried removing the router and connecting my T40 to a netgear switch together with my other laptop.

Again when the T40 is switched off the link/activity lights on the NIC port do not illuminate or flash.

When I send an MP nothing happens.

Do I have an old/incompatible NIC driver?(not saving settings) I would expect the link led to remain on and the activity light to flicker (when laptop is off) like my desktop does.

[Wiz]

Actually you can make WOL work through a router. When using WOL you send the magic packet (a packet that contains the MAC address 3 times for the computer you want to wake up). As EOMtp said the arp table will be purged so it won't work if you send the magic packet directly to the IP adresse of the computer. Actually the computer is turned off so it doesn't have a IP address anymore.
If you send the magic packet to the IP address the computer had before turned off your router will send a arp request (as long as it's not in the arp table of the router) and never receive a reply. If you try shortly after the computer is turned off and the entry still is to be found in the arp table of the router it might work if course, but it will be purged from the arp table pretty fast by default on most routers. The computer will only wake up if the computer receive the magic packet and will not repond to any arp request or any other traffic at all of course.

So you need to the send the packet to the broadcast address of the subnet where the computer you want to wake up are located. So if the network address are 192.168.1.0 with the subnetmask 255.255.255.0 then the broadcast address is 192.168.1.255. In that case you send the magic packet as a unicast to the IP address 192.168.1.255. Since this is the broadcast address the unicast packet will be forwarded as a broadcast to all addresses in the 192.168.1.0/24 subnet from your router and the computer should receive the packet. When you do this from the internet you have to setup the port forwarding to the broadcast address (192.168.1.255 in this example). Also the UDP port could be anything as long as the program you use have the option to choose the port number to use when sending the magic packet. The computer is only looking for one thing which is the magic packet (3x the MAC address).

To make this work "IP directed broadcast" have to be supported by your router. I work mostly with Cisco routers (not Linksys) and they have the option to turn on IP directed broadcast which is disabled by default since it's used in the common "smurf" denial of service attack. If you google for "WOL ip directed broadcast" you can find more info. Most of the routers to use at home doesn't have a lot of advanced features so that could be a problem. You might find out it's not possible with some kind of routers.

Also some routers have the option to create a static entry in the arp table which should work as well, but then the computer must have a static IP as well or you will mostly experience some problems if the IP change. If IP directed broadcast is supported this is a much better option i think.

[EOMtp]

Wiz is absolutely correct in the posting above.
Bottom line: one needs a router and/or switch which supports "advanced" features -- features which are not supported by any of the "home"-type (under $100 ... or even < $300) devices.

[Harryc]

I've used magic packet WOL before. It works off of the subnet mask and the MAC address of the target machine, both of which have to be configured in the packet sending software. I don't recall having to mess with IP addresses. It worked fine here...Cisco router and a switch. To the OP, have you enabled WOL in BIOS?

[Wiz]

I forgot to mention one thing regarding your computer. If i remember correctly the link led on your computer should not be off when using WOL. Also on the switchport there should be a light as well just like when the computer is turned on (unless your switch does not have a light for each port). I have a Cisco switch and the inface have a light which is on when the computer is off and WOL enabled. Also on the switch i can see the status of the port which is up/up. When no link it says down/down on the Cisco switch.

Before you try to make it work over the internet you could try to make it work with two computers on the same LAN/switch. If that's not working the program you use to send the MP might not work or the WOL does not work on the other computer.

Anyway before you even try to make it work you should make sure there is a link on the NIC/switchport when turned off and WOL enabled. Most switches have a light to indicate if there is a link or not. If no link the computer will for sure never receive the MP and you should try to figure out why WOL is not working on that computer. It has nothing to do with the driver or anything like that. If the NIC support WOL you should have a option in BIOS to enable/disable on a Thinkpad. You could check if there a BIOS update and read the release notes.....maybe there is some fixes for WOL.

[EOMtp]

I've used magic packet WOL before.

Harryc, there is no point in debating or arguing about this. One either has a switch which does not purge its ARP table ..or.. one is out of luck with regard to WOL. There is no third possibility. You are one of the "lucky" ones with your switch.

[Harryc]

LOL..well I must have been really lucky then..I paid $15 for the Nway switch and $70 for the Cisco

[Wiz]

I've used magic packet WOL before. It works off of the subnet mask and the MAC address of the target machine, both of which have to be configured in the packet sending software. I don't recall having to mess with IP addresses. It worked fine here...Cisco router and a switch. To the OP, have you enabled WOL in BIOS?

Did you send the MP over the internet or from another subnet then the computer you tried to wake up? In that case it's really easy, but when the sender are located in another subnet you have to use the "IP directed broadcast", static arp entry or a very long timeout (which is a very bad idea).

When using most Cisco equipment it's also no problem because that equipment have a lot of advanced feature you most likely cannot find in a home type of router like EOMtp also said. The switch is not that important, but the router is where you need more features like "IP directed broadcast".

When the router support IP directed broadcast you can send the unicast MP to the broadcast address and the router will forward the packet as a broadcast.....in that case the switch could be anything.....even the cheapest you can find.

[EOMtp]

...Nway switch...

That's great if those work! What is the model number of the Nway switch? I would love to get a few!

[Harryc]

Did you send the MP over the internet or from another subnet then the computer you tried to wake up?

No, we're talking about a single subnet simple home LAN here. I seriously doubt the OP is in a complex environment since he's referring to a personal ADSL router ...

[Wiz]

No, we're talking about a single subnet simple home LAN here. I seriously doubt the OP is in a complex environment since he's referring to a personal ADSL router ...

I agreee, but since myT40xxx999 said he setup the router to allow UDP/7 i just assume he want to use WOL over the internet and then from another subnet.

[Harryc]

...Nway switch...

That's great if those work! What is the model number of the Nway switch? I would love to get a few!

Gigafast Ethernet 5 port Nway switch

[Harryc]

T40xxx999 said he setup the router to allow UDP/7 i just assume he want to use WOL over the internet and then from another subnet.

True, I missed that... I never tried to use WOL outside of this simple home LAN.

[EOMtp]

Gigafast Ethernet 5 port Nway switch

Thank you. I wonder if their gigabit switches behave the same way as this one with respect to the ARP table.

[Harryc]

Gigabit...now your getting into a speed I have not arrived at locally

[Wiz]

Thank you. I wonder if their gigabit switches behave the same way as this one with respect to the ARP table.

The arp table is actually a layer 3 feature so the switch does not need or use any arp table. Some layer 2 switches have a arp table, but it's not used for the traffic that pass through the switch in any case so the behavior will be the same. If you are talking about a layer 3 switch (router and switch feature in the same box) that's a different thing, but then the router function of the box is using the arp table and not the switch. If we are talking about the mac table then it's a layer 2/switch feature.

[EOMtp]

If we are talking about the mac table ...

Yes, you are correct. We are talking about ARP table for the router, MAC table for the Layer 2 switch. (Sorry for the "sloppy" language!)

[myT40xxx999]

If you plug the charger in it WORKS!

Probably makes sense or is it a power saving setting somewhere?

Just to confirm - I have the latest firmware v3.23, the WOL is switched on in BIOS and my adsl router is a Speedtouch 580 with 'advanced' configs all over the place.

Thanks for your help, I will play/experiment with it.