Windows 10 RS4-17650, NETBios Resolution Issue

Copper Contributor

Windows 10 RS4-17650, we are facing issue related to discovery of printer device with netbios name. When we ping the device from console with netbios name in  upper case ,we get the error "Ping request could not find the host XXXX . Please check the name and try again". "XXXX" is the netbios name of Printer device. But we get response from device when netbios name is pinged in lower case.


We confirmed from device side that the response is sent for both case(ping from lower and upper case of netbios  device name).



In windows 8.1,windows 10 BUILD 16287 RS3_release, device responds when pinged with both lower/upper case netbios name.


6 Replies
I suspect that you mixed up NetBIOS and DNS. NetBIOS name is sent only in upper case, and "ping" utility uses DNS name which is usually in lower case, hence the difference. (There used to be a third "WINS" name resolution in the time of WinNT4/2k/2003, but less relevant today) Btw, in your network adapter settings, check your TCP/IP settings to verify whether NetBIOS over TCP/IP has been enabled.

Also this one:

In our .NET application, we are trying to discover the device by using DNS class and ping class i.e., When DNS fails, Ping takes over to discover the device accordingly. Both process are failing in the mentioned version of windows 10. I hope this the right place for this problem.

1) In windows 10 RS3_release, even though NetBIOS over TCP/IP is not enabled, device is discover-able by its netbios(UPPERCASE) name.
2) In windows 10 RS4-17650, even after enable NetBIOS over TCP/IP as suggested in the post doesn't discover the device.

I have two independent systems/networks with 4 machines. All 4 use fixed IPV4 addresses. All 4 are on Window 10 Version 1803(17134.48). NetBIOS over TCP is not enabled on any of the machines. On one pair, I can ping to UPPERCASE, uppercase, and UpperCase is each direction and the names resolve. On the other pair full uppercase and full lowercase work for ping, but mixed case does not. Enabling NetBIOS over TCP does not help.

Just to say I've got the same problem on 1803. Only one machine exhibits the problem. Ping fails (no LLMNR request is broadcast as shown by Wireshark) if the hostname in the ping matches the destination machine hostname exactly in the same case. PING UPPERCASE fails with "could not find host" if the destination machine is set to UPPERCASE whilst all other case variations (lowercase and MiXed) succeed, If you change the destination machine computername to lowercase then PING lowercase fails with "could not find host", whilst all other case variations (UPPERCASE and MiXed) succeed.

In both scenarios PING UPPERCASE. <trailing Dot) and PING lowercase. succeed.

This is similar to a problem mentioned here.

but the solution of adding a "." appended DNS domain does not seem to resolve this problem.

Definitely something wonky in 1803.

ping all lower case does not work for me, but ping all UPPERCASE does. 

ping lowercase with dot at the end, and ping all UPPERCASE works in here.