sudo mount -t cifs '\1.2.3.4/users/shared/chuck/subdir' /home/comp/mnt/subdir -o username=chuck,password=CR4gilson
mount error(115): Operation now in progress
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

Feb 15 09:43:56 ubuntucomp kernel: [7519048.289580] CIFS VFS: Error connecting to socket. Aborting operation.
Feb 15 09:43:56 ubuntucomp kernel: [7519048.289872] CIFS VFS: cifs_mount failed w/return code = -115

Samba                      ALLOW       Anywhere

$ telnet 1.2.3.4 445
Trying 1.2.3.4...
Connected to 1.2.3.4.
Escape character is '^]'.