All MAC addresses are identical

Howdy,

Every network scan I do works great, except all the MACs are the same (6C13D5BEEF5F). I don't know what options I should be looking at. The Detect duplicate MACs helpfully tells me that all the MACs are duplicates.

Any suggestions or ideas are greatly appreciated.

Thanks,
Pat

This usually happens because of either:

WiFi range extender/repeater

If your devices are behind a WiFi range extender or repeater, it would look like the devices have different IP addresses, yet the same MAC address. A range extender typically hides devices behind itself and does not retain their MAC addresses. You can type arp -a in a command prompt and observe the same behaviour.

One way around this issue would be to enable the WDS mode (Wireless Distribution System). The advantage of WDS is that it preserves the MAC addresses of client frames across links between access points. The drawback of WDS is that devices from different vendors may not be compatible with each other.

Scanning a different subnet

If you are scanning a different subnet, the default gateway may respond to every ARP request with its own MAC address rather than the target device's address, thus misleading the Network Scanner. Furthermore, when that happens, it may appear that all IP addresses are online even those that are not assigned. A workaround for this is to set the ping method to ICMP only rather than Both ICMP and ARP.

We have a dedicated article on this issue: Scanning non-local subnets and MAC addresses.

Thank you, Andrew!

I ended up using ICMP Only, NETBIOS, and router SNMP. No ARP or WMI.