One computer can't ping another, but the problem is one-way

[Gilbo]

I've got an odd networking problem that's driving me batty this Sunday afternoon. I tried to RDP into one of my home computers from another one this afternoon and RDP failed to connect. So pinged the computer, and 100% timeouts. I walked over to the computer and verified it was on. Checked the IP configuration and it had the right address which it receives via a DHCP reservation.

So I decided to ping the computer that I was trying to RDP from from the computer that I was RDPing to (i.e. just going back the other way). There was no problem.

So HOMEOFFICE1 can't see BIKEDESK, but BIKEDESK can see HOMEOFFICE1.

I've renewed the IP addresses on both machines. Rebooted both machines. I can't even think of what to do. BIKEDESK just seems to be invisible from HOMEOFFICE1.

Any ideas? I'm baffled. It's such a simple problem that I feel like I'm missing something obvious, but I've kind of thrown up my hands at the moment!

 

[Gilbo]

Hmmm. The plot thickens. I booted up another computer, HOMEOFFICE2, and tried to ping BIKEDESK. HOMEOFFCE2 couldn't get a response from BIKEDESK either.

But, again, BIKEDESK could ping HOMEOFFICE2. So, in both cases BIKEDESK can ping out, but other machines can't ping in. Obviously RDP was a no go from that machine too.

BIKEDESK is on the other side of a small 5-port GbE switch, rather than directly connected to the same switch as HOMEOFFICE1 & HOMEOFFICE2. HOMEOFFICE1 & HOMEOFFICE2 can ping each other and RDP into each other just fine and they're on the same switch.

But BIKEDESK gets its IP address from the Gateway just fine and has internet. Other computers on the network just can't seem to connect to it.

Ideas?

 

[timwhit]

Boot the unreachable system from a Bootable USB Linux distro and see if it can be pinged.

 

[Gilbo]

Bah. It thinks it's on a Public network in network locations. I guess Windows 10 firewall rejects ICMP packets and even authenticated RDP connections when it thinks it's on a Public network.

I'm Googling on how to change the Network Location setting from Public to Private, but it looks like that is actually non-trivial...

EDIT: And by the way, the reason this happened is because this is the one computer I upgraded to Windows 10 rather than did a clean install on. Now it's stuck thinking it's on a Public network and won't connect to any other machines...

EDIT 2: And the setting in Homegroups to change the Network Location type isn't available for me because UAC is set to "Always Notify". Thank god for Google. This is too many steps Microsoft...

 

[Gilbo]

Sorry for posting before doing as thorough a Google as I should've!

Basically I was able to change the Network Location from Public to Private by:
1. Lowering UAC from "Always Notify" (highest) to the 2nd highest setting.
2. Going to Homegroups, and clicking "Change network location" (this isn't available unless you do (1)).

Hopefully this helps some other poor soul who foolishly upgraded a computer on his home network to Windows 10 only to find out that all connectivity was subsequently disable, including even responding to pings...

EDIT: And thanks for the help Timwhit! Thankfully it didn't come to that...

 

[CougTek]

This is (was) a firewall problem on BIKEDESK. The name Microsoft gives to various network categories is only the way its firewall behaves towards those networks. If you can ping any computer from BIKEDESK but no computer can get an answer from BIKEDESK, then it's because the rules in BIKEDESK's firewall are too strict.

 

[Stereodude]

Been there done that. File and print sharing has similar issues if your PC thinks the network is Public.

 

[ddrueding]

Yup. When working with most vendor application issues, the step after "reboot" is "disable firewall and see if it works".

 

[Gilbo]

Ya, definitely should have thought firewall as soon as I realized it wasn't talking back but had network connectivity...

 

[mubs]

Hopefully this helps some other poor soul who foolishly upgraded a computer on his home network to Windows 10 only to find out that all connectivity was subsequently disable, including even responding to pings...

Thanks Gilbo, good to know.

 

[Mercutio]

Windows 8+ can sometimes have weirdness related to defaulting a network connection to Public if it thinks for some reason that it's been connected to a new network and/or if an OS upgrade has been applied. Some of my classroom desktops have two LAN ports so even connecting an ethernet cable to the other port from the one where it was installed was a problem until I decided to set the group policy entry to force all connections to one of the less restrictive options.