If this all works, then go back to OS/2 and use the command smbclient \\xxx.xxx.xxx.xxx\sharename using your Windows host IP address and Windows sharename. You hopefully will connect to the share and have an smb command prompt "smb: \>". You can then issue a "dir" command to list the files in your share as you had done on your Windows machine.
While doing the above might seem like a PITA, it's helpful to diagnose where you might be having a problem. If the above works, then you should be able to get NetDrive configured and working with the above IP address, workgroup and sharename.
I'm there: the above works. But getting same error alert after having filled the configuration of smbfs plugin values.
Repeat, maybe I'm missing the correct way to input values in the fields or else the smbfs plugin version 2.1.5 does not match the 4.9.4-4 samba client version installed by yum-rpm, but it looks like I've almost done it, just need the final push.
Thank you