Network Ports

In computer networking, there are network port numbers used for various applications. The range of these network ports are from 0 to 65535. There are three different port types used networking. These network port types are given below:


  • Well-known Ports (0 – 1023)
  • Registered Ports (1024 – 49151)
  • Dynamic Ports (Private Ports) (49152 – 65565)


Some of these port numbers are well-known ports. These well-known ports are the reserved ports between 0 and 1023. The full list of these network port numbers are given in RFC 1700. IANA (Internet Assigned Numbers Authority) assigns these well-known ports.


The other network ports are registered ports between 1024 and 49151. These ports are assigned by IANA for specific services.


The last part of ports in networking are dynamic ports. Daynamic ports are the ports from 49152 to 65565. These ports in networking are not registered with IANA.


TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) uses these well-known ports. Only one port is required for full-duplex, bidirectional traffic. Beside SCTP (Stream Control Transmission Protocol) and DCCP (Datagram Congestion Control Protocol) use these ports.


You can download the Cheat Sheet about Well-known network ports.



Well Known Ports in Networking

Well-known network ports are from 0 to 1024. These port numbers are given by IANA (Internet Assigned Numbers Authority). And the full list of these port numbers are in RFC 1700.


Some of these  well-known ports are used by TCP and some of them are used UDP. These TCP and UDP ports are also asked in many network engineering technical interviews as interview questions. So, what are these ports in networking?


Well-known TCP ports are the network ports used by the applications that works with TCP as transport protocol. So, what are these applications that uses well-known TCP ports?


For example, FTP (File Transport Protocol) is one of the applications that uses TCP ports. The FTP ports are TCP port 20 and TCP port 21. The other applcation that uses TCP as transport protocol is Telnet. Telnet uses TCP port 23.


Well-known UDP ports are the network ports used by the applications that works with UDP as transport protocol. So, what are these applications that uses well-known UDP ports?


For example TFTP (Trivial File Transport Protocol) is one of the applciations that uses UDP ports. UDP port 69 is used by TFTP. Another example that uses UDP as transport protocol is SNMP. SNMP uses UDP port 161 for SNMP and UDP port 162 for SNMP trap messages.


Below, you can find all the wellknown ports used by the applications that uses TCP & UDP network ports.


Port TCP UDP Name Description
1 tcpmux TCP port multiplexer
5 rje Remote job entry
7 echo Echo service
9 discard Zero service for test purposes
11 systat System information
13 daytime Time and date
17 qotd Sends quote of the day
18 msp Sends text messages
19 chargen Sends an infinite character string
20 ftp-data FTP data transfer
21 ftp FTP connection
22 ssh Secure Shell Service
23 telnet Telnet service
25 smtp Simple Mail Transfer Protocol
37 time Machine-readable time protocol
39 rlp Resource location protocol
42 nameserver Name service
43 nicname WHOIS directory service
49 tacacs Terminal access controller access control system
50 re-mail-ck Remote mail checking
53 domain DNS name resolver
67 bootps Bootstrap protocol services
68 bootpc Bootstrap client
69 tftp Trivial file transfer protocol
70 gopher Document search
71 genius Genius protocol
79 finger Delivers user contact information
80 http Hypertext transfer protocol
81 Torpark: Onion routing (unofficial)
82 Torpark: Control (unofficial)
88 kerberos Network authentication system
101 hostname NIC host name
102 Iso-tsap ISO TSAP protocol
105 csnet-ns Mailbox mail server
107 rtelnet Remote telnet
109 pop2 Post office protocol v2 for e-mail communication
110 pop3 Post office protocol v3 for e-mail communication
111 sunrpc RPC protocol for NFS
113 auth Authentication service
115 sftp Simple file transfer protocol
117 uucp-path File transfer between Unix systems
119 nntp Transfer of messages in news groups
123 ntp Time synchronization service
137 netbios-ns NETBIOS name service
138 netbios-dgm NETBIOS datagram service
139 netbios-ssn NETBIOS session service
143 imap Internet message access protocol for e-mail communication
161 snmp Simple network management protocol
162 snmptrap Simple network management protocol trap
177 xdmcp X display manager
179 bgp Border gateway protocol
194 irc Internet relay chat
199 smux SNMP UNIX multiplexer
201 at-rtmp AppleTalk routing
209 qmtp Quick mail transfer protocol
210 z39.50 Bibliographic information system
213 ipx Internetwork packet exchange
220 imap3 IMAP v3 for e-mail communication
369 rpc2portmap Coda file system port mapper
370 codaauth2 Coda file system authentication service
389 ldap Lightweight directory access protocol
427 svrloc Service location protocol
443 https HTTPS (HTTP over SSL/TLS)
444 snpp Simple network paging protocol
445 microsoft-ds SMB over TCP/IP
464 kpasswd Kerberos password change
500 isakmp Security protocol
512 exec Remote process execution
512 comsat/biff Mail client and server
513 login Login to remote computer
513 who Whod user logging daemon
514 shell Remote shell
514 syslog Unix system logging service
515 printer Line printer daemon print services
517 talk Talk remote calling
518 ntalk Network talk
520 efs Extended file name server
520 router Routing information protocol
521 ripng Routing information protocol for IPv6
525 timed Time server
530 courier Courier remote procedure call
531 conference Chat over AIM and IRC
532 netnews Netnews newsgroup service
533 netwall Emergency broadcasts
540 uucp Unix-to-Unix copy protocol
543 klogin Kerberos v5 remote login
544 kshell Kerberos v5 remote shell
546 dhcpv6-client DHCP v6 client
547 dhcpv6-server DHCP v6 server
548 afpovertcp Apple filing protocol over TCP
554 rtsp Real time streaming protocol
556 remotefs Remote file system
563 nntps NNTP over SSL/TLS
587 submission Message submission agent
631 ipp Internet printing protocol
631 Common Unix printing system (unofficial)
636 ldaps LDAP over SSL/TLS
674 acap Application configuration access protocol
694 ha-cluster Heartbeat service
749 kerberos-adm Kerberos v5 administration
750 kerberos-iv Kerberos v4 services
873 rsync rsync file transfer services
992 telnets Telnet over SSL/TLS
993 imaps IMAP over SSL/TLS
995 pop3s POP3 over SSL/TLS



Registered Network Ports

Registered networking ports start from port 1024 to 49151. IANA (Internet Assigned Numbers Authority)  assigns these registerd network ports. Below, you can find these registered networking ports


Port TCP UDP Name Description
1080 socks SOCKS proxy
1433 ms-sql-s Microsoft SQL server
1434 ms-sql-m Microsoft SQL monitor
1494 ica Citrix ICA client
1512 wins Windows internet name service
1524 ingreslock Ingres DBMS
1701 l2tp Layer 2 tunneling protocol/Layer 2 forwarding
1719 h323gatestat H.323
1720 h323hostcall H.323
1812 radius RADIUS authentication
1813 radius-acct RADIUS access
1985 hsrp Cisco HSRP
2008 Teamspeak 3 accounting (unofficial)
2010 Teamspeak 3 web list (unofficial)
2049 nfs Network file system
2102 zephyr-srv Zephyr server
2103 zephyr-clt Zephyr client
2104 zephyr-hm Zephyr host manager
2401 cvspserver Concurrent versions system
2809 corbaloc Common object request broker architecture
3306 mysql MySQL database service (also for MariaDB)
4321 rwhois Remote whois service
5999 cvsup CVSup
6000 X11 X Windows system services
11371 pgpkeyserver Public keyserver for PGP
13720 bprd Symantec/Veritas NetBackup
13721 bpdbm Symantec/Veritas database manager
13724 vnetd Symantec/Veritas network utility
13782 bpcd Symantec/Veritas NetBackup
13783 vopied Symantec/Veritas VOPIE
22273 wnn6 Kana/Kanji conversion
23399 Skype (unofficial)
25565 Minecraft
26000 quake Quake and other multiplayer games
27017 MongoDB
33434 traceroute Network tracking



Dynamic Networking Ports

Registered networking ports are the ports from 49152 to 65565. These ports can be used locally or dynamically by the applications. They are not assigned by IANA.



Network Ports Practice

Quesitons For Networking Ports

Question 1: Which network port range is reserved as Well-known Ports?

a) 0 – 1024

b) 1024 – 49151

c) 49152 – 65565

Question 2: Which network port range is reserved as Registered Ports ?

a) 0 – 1024

b) 1024 – 49151

c) 49152 – 65565

Question 3: Which network port range is reserved as Dynamic Ports ?

a) 0 – 1024

b) 1024 – 49151

c) 49152 – 65565

Question 4: Network port numbers are assigned by ….

a) ITU



d) ISO

Question 5: Which ones are the default network ports for FTP ?

a) UDP 20, 21

b) TCP 20, 21

c) UDP 22,23

d) TCP 22,23

Question 6: Which ones are the default SNMP Ports?

a) UDP 157, 158

b) TCP 157, 158

c) UDP 161, 162

d) TCP 161, 162

Question 7: What is the default Telnet port?

a) TCP 20

b) TCP 21

c) TCP 22

d) TCP 23

e) TCP 24

Question 8: Which ones are the default TFTP Port?

a) UDP 69

b) TCP 69

c) UDP 58

d) TCP 58

e) UDP 45

Question 9: TCP Port 25 is the default network port of ….



c) Telnet


e) FTP

Question 10: UDP Port 123 is the default network port of ….



c) NTP



Answers: 1)a    2)b   3)c    4)b    5)b    6)c   7)d    8)a  9)d  10)c


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CCNP Enterprise 350-401 ENCOR