Port Number – Basics

Port, may be an application specific or process specific endpoint to a logical connection. This tells a way a client program specifies a specific server program on a computer in a network. The port acts as a contact port for an application or a process in the host system. Port numbers determine the logical endpoints of a connection.
Based on port numbers, ports are mainly classified as:
Well known port numbers – These are a subset of numbers which are assigned to the application. The server usually provides its service on a well-known port. Used in the range of 1 to 1023 and managed by IANA (Internet Assigned Numbers Authority).
Registered port numbers – These are also used by applications but in the range of 1024 to 65535. These are not managed by IANA.
Reserved port numbers – Port numbers in the range of 1 to 1023 are called reserved port numbers. Applications like Login, SSH etc use the reserved port numbers as a part of authentication between client and server.
Reserved port numbers
Port Number                     Application
1                                                                     TCP Port Service Multiplexer
7                                                                     ECHO
20                                                                 FTP—Data
21                                                                 FTP—Control
22                                                                 SSH Remote Login Protocol
23                                                                 Telnet
24                                                                 SMTP
42                                                                 Host Name Server
49                                                                 Login
53                                                                 DNS
69                                                                 Trivial FTP
80                                                                 HTTP
109                                                              POP2
110                                                              POP3
118                                                              SQL Services
156                                                              SQL Server
161                                                              SNMP
389                                                              LDAP
443                                                              HTTPS
546                                                              DHCP Client
547                                                              DHCP Server

One thought on “Port Number – Basics

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s