What is Port?

1. When referring to a computer or device, a hardware port resembles a plug-in or connection commonly found on the back of a computer. Hardware ports allow computers to have access to external devices such as computer printers. Below is a short listing of the different computer ports you may find on a computer.
   
   AT Port (Old Keyboard Port)
   Firewire port
   LPT Port (Printer Port)
   PS/2 Port (Keyboard Port and Mouse Port)
   Serial Port
   Sound in and Line in
   Sound out and Line out
   USB Port
   
2. Term used to describe the process of taking a program that has been written for specific operating systems and moving it to another operating system. For example, taking a program written for Microsoft Windows and moving it to Linux.
3. When referring to a network or to the Internet, a software or network port is a location where information is sent through. A commonly used and accessed port is port 80, which is the http port. A listing of commonly known and used ports can also be found on the below listing. Users running Microsoft Windows can utilize the netstat command to view currently active connections that include ports currently being used.
   
   Users who wish to block ports on their computer or network can use a software or hardware firewall. If you are unable to get access to a particular port it's likely that a firewall is already present on the Network or other network settings set by the administrators have been setup.

Port	Protocol	Description
0		Reserved
1	TCP	TCP Port Service Multiplexer
5		Remote Job Entry
7	TCP, UDP	ECHO
9	TCP, UDP	Discard
13	TCP, UDP	Daytime - RFC 867
17	TCP, UDP	Quote of the Day
18	TCP, UDP	Message Send Protocol
19	TCP	Chargen - RFC 864
20	TCP	FTP - Data
21	TCP	FTP - Control
22	TCP	SSH Remote Login Protocol
22	UDP	PCAnywhere
23	TCP	Telnet
24		Private e-mail system
25		SMTP
27	TCP	ETRN
33		Display Support Protocol
35		Private print server
37	TCP, UDP	Time - RFC 868
38	TCP, UDP	Route Access Protocol
39	UDP	Resource Location Protocol
42		Nameserv (Host Name Server)
43		Whois
47		NI FTP
48		Default Audit Daemon
49		Login
50		Remote Mail Checking Protocol
52		XNS Time Protocol
53		DNS
57		Private terminal access
58		XNS mail
59		Private file service
60		NI mail
63		whois++
65		TACACS-Database Service
66		Oracle SQL*NET
67		Bootstrap Protocol Server, DHCP
68		Bootstrap Protocol Client, DHCP
69		TFTP
70		Gopher
75		Private dial out service
79		Finger
80		HTTP
80	TCP	Dungeon Siege game
81		HOSTS2 Name Server
82		XFER Utility
87		Any private terminal link
88		Kerberos, XBOX 360
89		SU/MIT Telnet Gateway
92		Network Printing Protocol
93		Device control Protocol
95		SUPDUP
98		TAC news
103		X400
106		3COM-TSMUX
107		Remote Telnet Service
108		SNA Gateway Access Server
109		POP2 (Post Office Protocol version 2)
110		POP3 (Post Office Protocol version 3)
115		Simple File Transfer Protocol
118		SQL Services
119		NNTP
130		CISCO FNATIVE
131		CISCO TNATIVE
132		CISCO SYSMAINT
135		Blaster worm
137		NETBIOS Name Service
138		NETBIOS Datagram Service
139		NETBIOS Session Service
143		IMAP
150		SQL-NET
151		HEMS
152		Background File Transfer Program
153		SGMP
154		NETSC
156		SQL Service
158		PCMail Server
161		SNMP
168		RSVD
179		Border Gateway Protocol
190		Gateway Access Control Protocol
200		AppleTalk Routing Maintenance
202		AppleTalk Name binding
204		AppleTalk Echo
206		AppleTalk Zone information
213		IPX
217		dBase Unix
219		Unisys ARP
220		Interactive Mail Access Protocol v3
256
258		Yak Winsock Personal Chat
263		HDAP
264		BGMP
280		HTTP-mgmt
315		DPSI
321		PIP
349		mftp
363		RSVP tunnel
366		ODMR
377		NEC Corporation
378		NEC Corporation
384		A Remote Network Server System
385		IBM Application
387		AppleTalk Update-Based Routing Protocol
391		SynOptics SNMP Relay Port
396		Novell Netware over IP
397		Multi Protocol Trans. Net.
402		Genie Protocol
406		Interactive Mail Support Protocol
413		SMSP
420		SMPTE
430		UTMPSD
431		UTMPSD
443		HTTPS
444		SNMP
445		Microsoft DS
458		Apple Quick Time
511		PassGo
514		Syslog
515		Spooler
519		Unix time
525		Time server
530		rpc
531		Chat
533		Emergency broadcasts
545		Apple Quick Time Server
546		DHCP Client
547		DHCP Server
563		SNEWS
565		whoami
568		Microsoft shuttle
569		MSN
585		IMAP4+SSL
666		Doom Id Software
711		Cisco TDP
799		ControlIT
989		FTP protocol, data, over TLS/SSL
990		FTP protocol, control, over TLS/SSL
992		Telnet protocol over TLS/SSL
993		IMAP4 protocol over TLS/SSL
994		IRC protocol over TLS/SSL
995		POP3 protocol over TLS/SSL
1025
1026
1080		Socks
1477		Microsoft SNA Server
1502		Shiva
1701		L2TP
1716		America's Army
1755		Microsoft NetShow
1812		RADIUS
2300	UDP	Dungeon Siege game
3074	TCP, UDP	XBOX 360
3389		Remote Desktop
3783	TCP	Gamespy
4000		ICQ
4000	TCP, UDP	Battle.net, Diablo, and Diablo II.
5190		AOL (AOL Instant Messenger - AIM)
5191		AOL 1
5192		AOL 2
5193		AOL 3
5631		PCAnywhere
5632		PCAnywhere
5800	TCP	VNC
5801	TCP	VNC
5900	TCP	VNC
5901	TCP	VNC
6073	UDP	Dungeon Siege game
6112	TCP, UDP	Battle.net
6113	TCP, UDP	Battle.net
6114	TCP, UDP	Battle.net
6115	TCP, UDP	Battle.net
6116	TCP, UDP	Battle.net
6117	TCP, UDP	Battle.net
6118	TCP, UDP	Battle.net
6119	TCP, UDP	Battle.net
6500		Net2Phone Registration
6667		IRC
6667	TCP	Gamespy
6801		Net2Phone
7000		VDOLive
7070		Real Audio
7075		Real Audio
8008		HTTP alternative
8080		HTTP alternative
9000	UDP	Asheron's Call game
9010	UDP	Asheron's Call game
9011	UDP	Asheron's Call game
9012	UDP	Asheron's Call game
9013	UDP	Asheron's Call game
12345		Port used by Trend Micro antivirus program. Port 12345 is also commonly used by variousTrojans such as Netbus.
12468		VXtreme
17770	UDP	Battlezone 2 game
17771	TCP,UDP	Battlezone 2 game
17772	UDP	Battlezone 2 game
26000		Quake game
27015	TCP	Half-Life
27900	TCP	Gamespy
28900	TCP	Gamespy
29900	TCP	Gamespy
29901	TCP	Gamespy
33334	UDP	Empire Earth game
33335	TCP	Empire Earth game
43188		ReachOut
47624	TCP	Age of Empires game, Baldur's Gate game, and Close Combat game