SOLVED: Can Connect To UNC Path With Host Name But Not the IP Address

This was a very unusual situation.  Normally we see computers unable to connect to a UNC share using the Host Name but being just fine with the IP address.  When you see this you almost certainly have a DNS issue.

This case was the other way around:

1. Can connect on \\<server host name>\<share name>
2. Cannot connect on \\<server IP address>\<share name>

When trying to connect to a share using the IP address, you may see:

Windows can’t find ‘\\<server IP address>\<share name>’.  Check the spelling and try again.

After working on this for 8+ hours including 4 hours with 3 different Microsoft support techs, we stumbled on the solution.   The last tech decided to try using the START command from CMD line and that brought up the following very useful error:

An attempt was made to logon, but the network logon service was not started

On the destination server START the NETLOGON service, and set it to automatic.

Bingo the problem was solved.

OTHER THINGS TO TRY WHEN YOU CANNOT CONNECT TO AN IP UNC PATH

If the above solution does not solve your issue there are several other items to consider:

1. Enable SMB 1.0 – Server 2016 and 2019 have SMB 1.0 disabled by default.  You can turn on SMB 1.0 via:
   1. SERVER MANAGER > ADD FEATURES (see screen shot to the right)
   2. Script – Enable-WindowsOptionalFeature -Online -FeatureName smb1protocol
2. Turn off the firewall and any other security software
3. Disable IPv6 – I have not seen this be a problem but Microsoft said they have seen it be an issue

BACKGROUND:

The server in question was running Windows Server 2012 without any problems but was upgraded to Windows Server 2016 and that is when this problem started.  We also found that for some unknown reason, Domain Admin’s COULD connect to the UNC share using the IP address.