In Explorer \\SUB2COMPUTER2 cannot access \\SUB1SERVER (0x80070035) even though can access \\SUB1COMPUTERi

In my company I have a main subnet, SUB1 (192.168.2.x/255.255.255.0), which includes \\SUB1SERVER, my domain controller (Windows Server 2003) and most computers (\\SUB1COMPUTERi).

I also have a second subnet, SUB2 (192.168.3.x/255.255.255.0), including only 2 computers, \\SUB2COMPUTER1 and \\SUB2COMPUTER2 separated from the first by a router. Both of these computers are running Windows 10.

Issue:

• \\SUB2COMPUTER2 cannot see \\SUB1SERVER and its shares in Windows Explorer, failing with error code 0x80070035 (network path not found)

Facts:

• \\SUB2COMPUTER1 (the other, nearly identical computer on SUB2 as well) can see \\SUB1SERVER and its shares OK in Windows Explorer
• \\SUB2COMPUTER2 can see \\SUB1COMPUTERi and their shares in Windows Explorer, the only issue is to see \\SUB1SERVER (so I assume the router separating SUB1 and SUB2 is configured OK)
• Running "ping SUB1SERVER" on \\SUB2COMPUTER2 works fine (so I assume the DNS resolution is functional)
• Firewall is disabled on \\SUB1SERVER
• Disabling Firewall on \\SUB2COMPUTER2 does not make a difference

What could make only \\SUB1SERVER invisible to \\SUB2COMPUTER2 in Windows Explorer even though \\SUB2COMPUTER2 and the router separating SUB1 and SUB2 are apparently configured OK and the DNS resolution is functional ?

Well, my answer does not really explain why \\SUB2COMPUTER1 could see \\SUB1SERVER while \\SUB2COMPUTER2 not, but it solved my issue so I guess it may close this issue.

So here it is: on \\SUB2COMPUTER2 I simply created a LMHOSTS file and added an entry for \\SUB1SERVER.

(Note that \\SUB2COMPUTER1 does NOT have a LMHOSTS file!)