Question about modem and computer.

[AWorriedPerson]

I know it is stupid question, but I know few about computers and this really is making me worried. When computer is shuted down, but connected to Internet then there should not be able for any malicious software, trojans or spyware to come and infect computer from Internet or if there is malicious software, trojans or spyware already in computer then they should not be able to download anything from Internet if computer is shuted down?

But when computer is shuted down sometimes modem lights "send or receive data" still blink, like there would be information flow between computer and Internet. I hope it is not some malicious thing in my computer sending information and downloading something from Internet even when my computer is shuted down.

[Bubba]

Originally Posted by AWorriedPerson

when computer is shuted down sometimes modem lights "send or receive data" still blink, like there would be information flow between computer and Internet

If We set aside for a moment that your motherboard is or is not equipped with Wake on LAN and strictly look at the modem light issue as if a PC was not even connected to it....We can then say "modem lights "send or receive data" still blink" is normal. Your ISP constantly sends out ARP packets to it's modems in order to resolve who is at a particular MAC addresses so it can identify itself to the network.

Why does my Cable Modem activity light flash rapidly ?

There is no need for concern: some essential data (DHCP and ARP protocols) is broadcast into the cable network and arrives at every cable modem whether your PC needs it or not. You need not worry that someone is trying to hack into your PC just because the data light is flashing.

[AWorriedPerson]

Originally Posted by Bubba

If We set aside for a moment that your motherboard is or is not equipped with Wake on LAN and strictly look at the modem light issue as if a PC was not even connected to it....We can then say "modem lights "send or receive data" still blink" is normal. Your ISP constantly sends out ARP packets to it's modems in order to resolve who is at a particular MAC addresses so it can identify itself to the network.

Why does my Cable Modem activity light flash rapidly ?

Thank you very much for your answer.

[GroomLake]

Exactly what kind of modem are you talking about?

[DVD+R]

Cable or ADSL Modems are conected to your ISP by what is called a line sync. This connection tells your modem that it is readily active. Turning Off the Modem cuts the connection, but this is generally not a good Idea as the Modem then again has to find the line sync before it can connect to the LAN. Nothing to worry about WorriedPerson. I leave my Modem on 24/7 with my computer powered off overnight. No data is being transfered to your computer,as your computer needs power to operate