WHAT IS PORT NUMBER tutorial

 

WHAT IS PORT NUMBER IN NETWORKING AND ITS USES

Port number is one of the most commonly discussed topics in a computer network. We always use to by heart the port number of POP3, SMTP, DHCP, DNS, etc and prepare for the interview. But have you ever searched for what is the port number, why do we need a port number, and what is the use of it. Hello friends, I am your host Abhishek Gupta and in this post, I am going to explain to you the basics of the port number in networking.

The Port number is a unique ID of a protocol in a computer network. Every protocol in a computer network has a unique ID, now the question is why do we need this port number, and what is the use of it.

Let’s take an example, in a network there are 10 computers connected together and out of 10 computers one is a DHCP server, and the remaining nine are DHCP hosts who all are getting IP Addresses from the DHCP server. How your computer network understands which one is a server and which one is the host.

It can be identified only from the port number. as we know that the DHCP protocol has two port numbers 67 (for server) and 68 (for the host). The PC assigned with the port number 67 is the server and all the other PC are assigned with the port number 68 is the host. This is how your computer network will understand which one is the DHCP server or host.

Let’s take another example, you might have noticed in the most popular mailing app outlook, we have to configure incoming mail server (POP) and Outgoing mail (SMTP) and have to assign the port number. Hence the POP port number 110 is without SSL (Encryption) on the other hand 995 is with SSL (Encryption). If you assign the port number 110, your outlook will understand this user is not using an encryption connection and if you assign 995, outlook will understand the user is using an encryption connection.

So, guys, this is the basic concept of the port number in computer networking. Hope you all enjoyed reading this.

List of most commonly used port number in networking:

Protocols                                                    Port No

FTP                                                                    21

TELNET                                                        23

HTTP                                                                    80

DNS                                                                    53

SSH (Secure Shell)                                            22

SMTP                                                                    25

DHCP Server                                                        67

DHCP client                                                        68

POP3 (Post Office Protocol, version 3)        110

NTP (Network Time Protocol)                    123

IMAP (Internet Message Access Protocol)    143

SNMP (Simple Network Management Protocol)161

IMAP3 (Internet Message Access Protocol 3)    220

SSL (Secure Socket Layer)                                443

NetBIOS (Network Bios)                                139

RIP (Routing Information Protocol)          520

What is Computer Network Topology 

Computer Network Topology Computer Network Topology is a structure or layout which defines how devices such as the hub, switch, router, PC, or any nodes are connected to the network. Topologies can be physical or logical. Physical topology refers to the actual structure of the network. Logical topology defines the way in which data actually.