Samba: How to configure share for guest access and how to mount the share without password?

Issue

• Samba: How to configure share for guest access and how to mount the share without password?
• Cannot mount samba share served by RHEL 7.2 to a RHEL 5.11 box, guest access failing.

#  mount -t cifs  //samba.example.com/tshare /mnt
mount error 13 = Permission denied
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)