Two devices on the same network cannot communicate with each other

[creatine]

Coming from an IT and networking background, I am embarrassed to be asking for help with something so basic.

I recently reinstalled Windows 10 (latest version) on 3 PCs in my home, since then these 3 devices cannot communicate with each other, ping, RDP, access file shares etc. All devices are connected to the same wireless network and receive IPs via DHCP from the router (AC3100 running Asus Merlin). I can see the PCs\IPs in the router log. All devices can ping the default GW, access the internet and can ping other devices on the same LAN (ex: firestick, doorbell camera, etc) but not each other. I disabled windows FW on the PCs, I do not have any other security software that can be interfering with communication. AP is set to "not isolated" I am at a loss as to why these devices can't communicate with each other. Is there a "Windows 10 setting" that can be causing this issue ?

 

[ColinTaylor]

Are all of these devices connected over WiFi? If so, are they all connected to the same AP, SSID and band on the main router or are they connecting to different APs?

In the Windows network settings are the PCs connected to a "Private network"?

 

[creatine]

Yes, all the devices are connected via wifi, same router/AP, same SSID, same band, etc. I only have a single router/AP in my setup. From a windows point of view, I disabled ipv6, made sure all 3 devices are in the private network, made sure network discovery and file sharing is turned on and disabled windows fw.

 

[ColinTaylor]

Can you ping other devices connected to the same AP?

What if you connect one of the PCs to a 2.4GHz SSID and another to an 5GHz SSID. Can they ping each other now?

Other than that can you post the complete output of ipconfig /all from one of the PCs.

 

[creatine]

I am able to ping other devices on the same AP (firestick, doorbell, etc) I don't want to jinx it, but I power cycled the router and pings seem to be behaving normally. I will keep testing.

As far as ipconfig goes, all devices are in the 192.168.1.0 /24 subnet. Default gw and DNS are the router at 192.168.1.1

 

[sfx2000]

Wireless AP isolation?

I forget at the moment where that setting is located in AsusWRT, but this does sound like that is the cause - esp. if each of the clients can get to the internet...

 

[creatine]

Its been 24 hrs, and everything is working as expected after a router\AP reboot. I can't explain the behavior as to why only the windows desktops were affected, but LAN communication is working for all devices.