On 12 Jul 2018 17:34:22 GMT, wrote:

Just a thought, but have you tried adding DESKTOP 192.168.107 to
your Hosts file?

As a debugging step, I documented that adding this to the HOSTS file
192.168.1.7 DESKTOP
works just fine - but that's a lousy workaround overall because it
should work without having to do add a static IP to the hosts file
just to get name resolution to work on Windows.

I'm sure if I add it to the LMHOSTS file, it will also work.
But that's not a "solution" - that's just an ugly workaround.

The problem is to figure out why NETBIOS isn't working on 1 computer.

Most of the people who have had this problem just threw commands at it,
which is what I've been doing up until now.

But now it's time to figure out how NETBIOS actually works.

To that end, this article seems useful:
How NetBIOS name resolution really works
"When NetBIOS problems occur they can be difficult to detect.
Understanding how NetBIOS works is the key"
https://www.techrepublic.com/article/how-netbios-name-resolution-really-works/

Apparently NETBIOS has four resolution steps:
1. The first resolution is to check the existing cache
2. The second resolution is to check the LMHOSTS file
%SYSTEMROOT%\SYSTEM32\DRIVERS\ETC\lmhosts
3. The third resolution is to contact a WINS server
4. The fourth resolution is a broadcast for the NETBIOS name

In this fourth step the TOPDESK PC will send a broadcast packet seeking the
DESKTOP PC which will respond *if* the DESKTOP PC gets that broadcast
packet - but - some routers may block that broadcast packet - so - I have
to find out if my transceiver is blocking the NETBIOS broadcast packet.

The first test of netbios name resolution is apparently this command:
From TOPDESK (giving the IP for DESKTOP below):
admin nbtstat -a 192.168.1.7
Node IpAddress: [192.168.1.7] Scope Id: []
NetBIOS Remote Machine Name Table
Name Type Status
---------------------------------------------
DESKTOP 00 UNIQUE Registered
WORKGROUP 00 GROUP Registered
DESKTOP 20 UNIQUE Registered
MAC Address = 00-23-58-E4-A6-F3
From DESKTOP (giving the IP for TOPDESK below)
admin nbstat -a 192.168.1.6
This works similarly to the above.

Note that the "00" means the "Workstation, Domain Name" resolved it.
And the "20" means the "File Server" resolved it.

Running that same command, but with the NETBIOS name instead, we get:
From DESKTOP:
admin nbtstat -a TOPDESK
Reports a successful resolution similar to the above.
From TOPDESK:
admin nbstat -a DESKTOP
This fails, reporting "Host not found."

On DESKTOP, I can display the cache using:
admin nbtstat -c
(which reported that TOPDESK was in the cache)
And I can clear the cache using:
admin nbtstat -R

When I tried the same on TOPDESK, there were "No names in cache",
which makes sense since it has never connected via NETBIOS to DESKTOP.

I'm pretty sure that the problem may very well be that the transceiver
attached to DESKTOP is "blocking" the NETBIOS broadcast requests.

One way to test that is to plug DESKTOP via Ethernet into the router
directly, thereby completely bypassing the WiFi transceiver, so that's what
I'll try next as a debugging step.

If that all of a sudden enables NETBIOS resolution, then my problem is in
the setup of the 2.4GH transceiver attached to the Ethernet which is
attached to the desktop (which doesn't have a WiFi card).

That transceiver is set to "Bridge" mode - and it may be blocking the
NETBIOS broadcast packets (I don't know that for a fact yet though).