Thursday, 23 March 2017

What is computer port anyway??

Hello guys, hope you all are fine. So let's get straight to the business. Today we are gonna learn about computer ports and why are they so important. So let's stretch the level of technology.
 Port are both hardware and software type. Hardware ports are like usb port, ethernet port, RJ-45port, VGA port etc. But we are going to discuss about port of computer network.


PORT: Port is an end point of a network just like a ship in a sea which has port where it stops. So, a network always has an end point which is called port. Every services running on computer uses a certain port just like a vehicle needs wheels to move. Port is also consider as a medium which separates each services on the network. You can relate this with a palace of king having many doors where each door is used for definite task as per protocol set up by the king. So, port is like a door also where each port holds the entry ticket for a definite service. As we know while surfing the web, we do not simply surf the web but also download or upload the files, play online games, watching live t.v, sending emails etc. So, for that reason we use various protocols which needs various ports. For example, to surf http (Hyper Text Transfer Protocol) web pages, we use http protocol which runs on port 80 of network.This port is used for surfing http web pages and disabling this port will result failure in access of any http web pages. Similarly, to transfer a file over internet we need ftp protocol i.e, to upload and download the files. Ftp (File Transfer Protocol) protocol runs over port 20. Similarly, udp (User Datagram Protocol) protocol is used for online gaming, watching live t.v which runs over port.
So each and every services of computer uses a definite port to run which is also a medium to separate each services on the network. Hence our system will understand that which service should be used for a definite task. For example mail server uses smtp (simple Mail Transfer Protocol) protocol which by default runs over port 25. Smtp protocol is used for mail services over the internet. We are giving you the picture of a simple port scanning result of our blog using kali linux.

 

Below we are giving you a few list of services along with the port over which they run.

Common Ports

Port No           Service
20                    FTP data (File Transfer Protocol)
21                    FTP (File Transfer Protocol)
22                    SSH (Secure Shell)
23                    Telnet
25                    SMTP (Send Mail Transfer Protocol)
43                    whois
53                    DNS (Domain Name Service)
68                    DHCP (Dynamic Host Control Protocol)
79                    Finger
80                    HTTP (HyperText Transfer Protocol)
110                  POP3 (Post Office Protocol, version 3)
115                  SFTP (Secure File Transfer Protocol)
119                  NNTP (Network New Transfer Protocol)
123                  NTP (Network Time Protocol)
137                  NetBIOS-ns
138                  NetBIOS-dgm
139                  NetBIOS
143                  IMAP (Internet Message Access Protocol)
161                  SNMP (Simple Network Management Protocol)
194                  IRC (Internet Relay Chat)
220                  IMAP3 (Internet Message Access Protocol 3)
389                  LDAP (Lightweight Directory Access Protocol)
443                  SSL (Secure Socket Layer)
445                  SMB (NetBIOS over TCP)
666                  Doom
993                  SIMAP (Secure Internet Message Access Protocol)
995                  SPOP (Secure Post Office Protocol)
1243                SubSeven (Trojan - security risk!)
1352                Lotus Notes
1433                Microsoft SQL Server
1494               Citrix ICA Protocol
1521               Oracle SQL
1604               Citrix ICA / Microsoft Terminal Server
2049               NFS (Network File System)
3306               mySQL
4000               ICQ
5010              Yahoo! Messenger
5190              AOL Instant Messenger
5632              PCAnywhere
5800              VNC
5900              VNC
6000              X Windowing System
6699              Napster
6776             SubSeven (Trojan - security risk!)
7070             RealServer / QuickTime
7778             Unreal
8080             HTTP
26000           Quake
27010           Half-Life
27960           Quake III
31337           BackOrifice (Trojan - security risk!)

Ports between 1024 and 29151 are known as the Registered Ports. Basically, programs are supposed to register their use of these ports and thereby try to be careful and avoid stomping on each other. Here are some common ports and their programs. For security reason you should check how many ports are open on your system and if there is any unnecessary port is open on your system then you should close that port.



Hope you found this piece of information useful. That's all for today. We will be back soon. Till then like, share and subscribe our blog.

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