NIC problem

[anirban]

the NIC is still sending signal though the computer is shut down. connected switch port is showing green led , and if the straight cable is plugged out from the NIC then the switch port is showing down.
another thing is if the computer is disconnected from the power after shut down then also the connected switch port is showing down.

what is the reason behind it?

 

[RealBlackStuff]

Your motherboard is on StandbyVoltage, as long as the PC mains power is ON. Switch the button to OFF on the back of the PC's powersupply, or disconnect mains cable from PC.
This is done so PCs can use their wake-up functions through modem/LAN/keyboard etc.
If you don't want or use this, disconnect completely (as above).