A brief set of instructions for checking whether there are any other Ethernet hosts on the same segment as you.
- a computer running Microsoft Windows
- an Ethernet IPv4 network
- nothing prevents you from sending ping requests
- nothing prevents any other hosts on your segment from receiving ping requests (this is a likely point of failure, since firewalls often reject or discard ping packets)
- Go to your Windows box. Find out your own IP address and subnet mask; this is done by typing ipconfig. Example: IP address 10.10.10.10, net mask 255.255.255.0.
- Look up the broadcast address for your network in RFC 1878. Continuing the above example, the broadcast address would be 10.10.10.255.
- Ping the broadcast address by typing e.g. ping 10.10.10.255 (using the broadcast address you found above). This should make all hosts on your segment advertise their MAC addresses to you.
- View your ARP cache by typing arp -a. You should see the IP address of your router. Any other IP addresses are other hosts on your segment.