12 Network Protocols Every IT Professional Should Know

Open Shortest Path First (OSPF) network protocols are a set of established rules that control and govern the exchange of information following a secure, reliable and simple method. These rule sets are present for several applications, such as wired networks (such as Ethernet), wireless networks (such as WLAN), and Internet communication. The Internet protocol suite, which is used to disseminate and transmit data over the Internet, comprises dozens of protocols. The Ethernet 802.3 protocol defines the physical layer in wired network models, as well as the medium access control (MAC) sublayer of the data link layer. There are several versions of the IEEE 802.3 protocol, for example, 10Base-T, 100Base-T, 1000Base-T, and 10GBase-T.

Each version is designed to work with different types of cables. Another widely used protocol is the IEEE 802.11, which specifies the physical layer and media access control (MAC) protocols for implementing the wireless local area network (WLAN). This protocol is a wireless computer networking standard and is used to allow laptops and smartphones to communicate without being connected with a cable. The main differences between 802.11 and 802.3 are in the sizes of the frames, fields, and the size of the data carried. The 802.11 Ethernet protocol has two more address fields than 802.3 and the frame body size is greater than 802.3 (a maximum of 1500 bytes for 802.3 and 2312 bytes for 802.11).

Standardized by the IEEE in 1974, this protocol is responsible for routing and fragmenting data packets in digital networks. Its goal is to ensure the successful delivery of packages from origin to destination. To do this, the IP specifies a format that defines the type of description of data packets, called IP datagrams. The main difference between IPv4 and IPv6 is the use of address space. The difference between these two is found in the header, where several fields are present in one header but absent in the other. The IPv4 format was revised and improved to IPv6, which is more efficient and less complicated.

Defined by the IEEE 802.1d, this protocol prevents loops in the LAN.


addresses issues related to bridged networks. It eliminates redundant links and processes network changes and failures.


also has some drawbacks. The data that can be sent via FTP is limited to 2 GB.

Therefore, any file larger than 2 GB cannot be transferred via FTP. In addition, it is not compatible with all systems. In this tutorial, we look at the 12 network protocols that are the most used and extremely popular. We present a concise introduction and some applications of these protocols. A strong network foundation forms the foundation of any successful IT career.

Learning the basics of networks requires absorbing and retaining a lot of information. As a result, networks can be difficult to learn, especially if you're new to IT. To that end, let's explore 12 important network protocols that every IT professional should know: IEEE 802.1Q, IP, HTTP, FTP, SMTP, SSH, Telnet, VNC, ARP, RARP, ICMP, and DNS.

IEEE 802.1Q

is more of a standard than a protocol, but it's just as important. Often referred to simply as dot1q, this is the standard for VLAN tagging.

It allows the multiplexing of different VLANs over the same cable by prefixing a VLAN header. Prior to this, OEMs had their own patented standards that were not interoperable. Dot1q allows multiple VLANs to be multiplexed over a single uplink or a set of uplinks. Without it, each VLAN would need its own uplink to the next switch; routers would also need separate uplinks for each VLAN. At layer 3, understanding how IP addresses and subnets work together with the routing of this traffic can help you solve problems related to traffic arriving at its destination.


is a higher-layer protocol used by applications.

This is important because it is widely used; not only are web pages and web services using it, but VPN tunnels and web sockets have also been known to use it. The use case for understanding HTTP is that most online services now use this; if there are performance issues or errors, it can be useful to understand the HTTP protocol. This is particularly true in the event that you have to resort to using a browser debugger to help determine an error; sometimes HTTP error codes are hidden or hidden in the HTTP results so that the browser doesn't show them but they are there.


is a legacy protocol that has been around for quite some time; it is still in use although other mechanisms or protocols are generally preferred when possible. It's usually a highly reliable protocol that allows you to send and receive files; this protocol has a few different methods and flavors so it's very useful to understand those nuances.


is a mail transmission protocol that has existed since the early 1980s and has been updated over the years; it's still the standardized method for mail servers to communicate with each other when transmitting emails.


has existed since the mid-1990s and has since been replacing legacy protocols such as telnet; SSH is an encrypted remote connection and file transfer protocol that continuously receives security updates as new encryption technology appears.


, on the other hand, is an application protocol used on the Internet or in a local area network (LAN) that provides two-way interactive text-oriented communication using a virtual terminal connection; we can easily communicate with people around the world using various network protocols, and therefore it plays a critical role in modern digital communications.


, or Virtual Network Computing, is used to establish remote desktop sharing which is a form of remote access in computer networks; network protocols are a set of rules that govern how computers communicate with each other over networks.

Deb Magby
Deb Magby

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