Keep lan connection alive while going to sleep

Question

Is it possible to keep lan connection alive when going to sleep? Although I would like a laptop independent(in general) answer, my laptop is Thinkpad T500 and the power manager shows in PCI options, the following three option regarding saving link state power: Off, moderate, maximum. Also instant resume apparently does something different, so that isn't much help either.

I'm on Windows-7.

Here's why:

I'm a student, and currently I keep my laptop on almost all the time, but sometimes I sleep it and then I require to check something, so I turn it on. But then internet starts in at least a minute. So I avoid even putting it to sleep. I want that the internet connection should persist, so that I can put it to sleep to avoid power consumption.

Answer 1

I don't think that the PC can continue Network activity while in sleep mode. If the issue is the PC going to sleep while downloading/using the network why not just disable the sleep mode? Maybe you already thought of that, but just checking ;)

Answer 2

A great question! I thought about this a few years back and there was nothing for it at the time. Now, it seems there has been progress on this front. Here's some info:

1. Enterprise PCs work while they sleep - saving energy and money - with new software
2. Microsoft's Sleep Server Can Green Corporate Networks
3. A Software-Only Approach for Reducing Energy Consumption

Answer 3

If you tell it to be wakeable from lan then the network card stays on in a almost-asleep state listening for magic packets. I believe it requires a BIOS setting, google "wake on lan" with your computer model. Most of the results seem to be about the drivers (so update them), but also this.