[masraum]

You can ping 224.0.0.1 and then arp -a.

224.0.0.1 is a special multicast address that requestes that all hosts on a network reply. And then with the arp -a you should see a list. You should actually be able to see the hosts as they reply so the arp -a is not 100% necessary. This may not work for PCs that have Windows XP firewall enabled.

Here's a sample of what you'd get.

H:\>ping 224.0.0.1

Pinging 224.0.0.1 with 32 bytes of data:

Reply from 10.20.166.254: bytes=32 time<1ms TTL=255
Reply from 10.20.166.118: bytes=32 time<1ms TTL=64
Reply from 10.20.166.118: bytes=32 time<1ms TTL=64
Reply from 10.20.166.118: bytes=32 time<1ms TTL=64

Ping statistics for 224.0.0.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

H:\>arp -a

Interface: 10.20.166.49 --- 0x10003
Internet Address Physical Address Type
10.20.166.102 00-0e-7f-e7-c1-63 dynamic
10.20.166.118 00-13-21-26-61-33 dynamic
10.20.166.254 00-0d-ed-c0-08-43 dynamic