NIC LED always on

[pingree]

I was working with a Sony VAIO computer yesterday, and which is being used on a peer-to-peer network, sharing an IP connection (cable modem) through a Seimens router. The VAIO has been showing intermittent connectivity; sometimes it has Internet functionality, and when it does, it works very well. It will then lose Internet access, and access to the other workstation. I believe it is a connection issue, with the "different" thing here being that the LED on the internal VAIO NIC is always green, even when the workstation is off. Hmmm...

I have used alternate patch cords, cabling, router setups, user id's/passwords. The workstation does not respond to the changes I make in any predictable way; it comes back up when nothing is different, and loses connectivity in mid-session. Is this a "bad" NIC? What's that always-green LED about?

Thanks