1.1 Understanding CIFS

The Common Internet File System (CIFS), also known as Server Message Block (SMB), is an application-layer network protocol used for providing shared access to files on a Local Area Network (LAN). It either relies on NetBIOS over TCP (NBT) via 139 port or bypasses NetBIOS and directly use TCP via 445 port for reliable transport. Although file sharing is the primary purpose of CIFS, there are other functions that CIFS is commonly associated with. Some of them include service announcements, name resolution, user authentication, authorization, and browsing for other CIFS servers in the network.

CIFS runs on the Open Enterprise Server (OES), uses NetIQ eDirectory services for eDirectory user authentication and kerberoes for AD user authentication. It allows Windows, Linux, and Mac client users to access the server data files or other shared resources in one of the following ways:

For Windows, through the Network Neighborhood or My Network, Windows Explorer, and mapped drives from Windows workstations.
For Linux, through an SMB client from Linux desktops.

Figure 1-1 CIFS Conceptual Overview

CIFS enables any SMB clients like Windows, Linux, and Mac client work stations and not limited to these desktop clients only to create, copy, delete, move, save, and open files on an OES server. CIFS allows read and write access from multiple client systems simultaneously. All these various file operations and sharing of resources on a network are managed from a CIFS server.