Utility protocols for Internet: SMB and AFP

Very first thing, you won’t find these protocols under the term utility but it is more like personal term for such protocols. The protocols that we are about to dig into are the kind of protocols, which are part of a large protocols. These protocols individually serves their own purpose to accomplish some specific task of large part of the network.

Hence, the term utility quite fits well for these protocols.

The most common protocols

It is doubted that you will ever need to deal with two the protocols below directly like LDAP and SNMP. The other, SMB is quite often touched on LANs but not the Internet. AFP is platform based which for macOS. SLP is typical for network-aware print devices. If you are new in the tech field of any sector, the following list of protocols will give you heads up.


Stands for Server Message Block (SMB) protocol. This protocol is what Window’s network file and print sharing uses. A similar but competing protocol is used in UNIX and Linux based systems, called Network File System (NFS) but this is somewhat rare now. Today, most of the Major operating System use SMB.

SMB is basically a client-server communication protocol used primarily for sharing resources like files, printers, serial ports and other resources on the network. SMB is capable of carry any transaction protocols for interprocess communication. SMB opens up secure and controlled method for opening, reading, moving, creating and updating files on remote servers. SMB is also able to communicate with server programs, which is configured to receive SMB requests. SMB is one of the most common protocol used for network communication.

There are number of SMB dialects or version has been taken place since its first launch, bring forth more robust and efficient features. Some of these dialects are SMB 1.0, which traces as back as 1984. CIFS, developed by Microsoft, which was debut in Windows 95. SMB 2.0, 2.1, 3.0, 3.02, 3.1.1 .


When Microsoft and SMB developed protocol how come Apple did not take part in the game? Of course they did. Apple developed the Apple Filing Protocol (AFP) in the late 1980s, which support file sharing between Macintosh computers on the early LANs. Like SMB, AFP survived to this day and used as a way for macOS machines to share files with other Macs, both new and old ones.

Support for AFP besides macOS is provided by Linux but Windows lack straight out of the box support for the protocol.


Stands for Service Location Protocol (SLP) which advertise available services over a local network to discover those services. Most commonly seen in network-aware printers and some OSs uses it for file sharing. Both the UDP and TCP port 427 is used in SLP.