Why don't neighboring machines on the network ping?

Question

Windows

The Internet is successfully distributed through the wifi router tplink td-w8951nd, the network filter in the router was turned off, as well as firewalls and antiviruses on both machines, which I included in the working group of the same name, the router rebooted the machines. But from the target machines I can only ping the router, the hosts themselves do not ping each other at internal addresses.

Answer 1

>> figured out the source of evil - enabled UAC, which for some reason did not allow the network participants grouping service to start, which was revealed when running a Windows utility to check and fix network problems

Answer 2

look in the router settings what IP addresses it gave to the connected computers

Answer 3

Check the arp tables ( arp -a) on the machines, probably the proxy ARP option is enabled on the router. Compare the contents of the entries with the real MAC addresses of the network adapters of the machines ( ipconfig /all)