Search for mac addresses over my network (show all even if the host pc is closed)

Question

Is it possible to search for all the mac addresses available in my network even if the computers are closed?

I used NetScan but it only show mac addresses for computers that are on.

BTW i`m running Windows 7 Pro.

Answer 1

If they are off? No, they have no way to respond.

Although you don't need a tool if they are on, ping the broadcast address for your network then grab them with arp:

C:\>ping 10.100.1.255

Pinging 10.100.1.255 with 32 bytes of data:

Reply from 10.100.1.235: bytes=32 time<1ms TTL=64
Reply from 10.100.1.235: bytes=32 time<1ms TTL=64
Reply from 10.100.1.235: bytes=32 time<1ms TTL=64
Reply from 10.100.1.235: bytes=32 time<1ms TTL=64

Ping statistics for 10.100.1.255:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\>arp -a

Interface: 10.100.1.174 --- 0x4
  Internet Address      Physical Address      Type
  10.100.1.175          00-03-ff-a2-c0-95     dynamic
  10.100.1.178          00-03-ff-46-df-1d     dynamic
  10.100.1.196          00-03-ff-49-0c-30     dynamic
  10.100.1.220          00-03-ff-46-99-37     dynamic
  10.100.1.227          00-03-ff-46-95-05     dynamic
  10.100.1.235          00-03-ff-46-de-1e     dynamic
  10.100.1.239          00-03-ff-46-9f-c1     dynamic