Port numbers are used to determine what protocol incoming traffic should be directed to. Ports allow a single host with a single IP address to run network services. Each port number identifies a distinct service, and each host can have 65535 ports per IP address. Port use is regulated by the Internet Corporation for Assigning Names and Numbers (ICANN). By ICANN there are three categories for ports

  • From 0 to 1023 – well known ports assigned to common protocols and services
  • From 1024 to 49151 – registered ports assigned by ICANN to a specific service
  • From 49152 to 65 535 – dynamic (private, high) ports range from 49,152 to 65,535. Can be used by any service on an ad hoc basis. Ports are assigned when a session is established, and released when the session ends.

Port #    Portocol               Description

0              TCP, UDP             Reserved; do not use

1              TCP, UDP             TCPMUX

5              TCP, UDP             RJE (Remote Job Entry)

7              TCP, UDP             ECHO protocol

9              TCP, UDP             DISCARD protocol

11           TCP, UDP             SYSTAT protocol

13           TCP, UDP             DAYTIME protocol

17           TCP, UDP             QOTD (Quote of the Day) protocol

18           TCP, UDP             Message Send Protocol

19           TCP, UDP             CHARGEN (Character Generator) protocol

20           TCP        FTP Protocol (data) - port for transferring FTP data

21           TCP        FTP Protocol (control) - port for FTP commands and flow control

22           TCP, UDP             SSH (Secure Shell) - used for secure logins, file transfers (scp, sftp) and port forwarding

23           TCP, UDP             Telnet protocol - unencrypted text communication, remote login service

25           TCP, UDP             SMTP (Simple Mail Transport Protocol) - used for email routing between email servers

26           TCP, UDP             RSFTP - A simple FTP-like protocol

35           TCP, UDP             QMS Magicolor 2 printer

37           TCP, UDP             TIME protocol

38           TCP, UDP             Route Access Protocol

39           TCP, UDP             Resource Location Protocol

41           TCP, UDP             Graphics

42           TCP, UDP             Host Name Server/WINS Replications

43           TCP        WHOIS protocol

49           TCP, UDP             TACACS Login Host protocol

53           TCP, UDP             DNS (Domain Name System)

57           TCP        MTP, Mail Transfer Protocol

67           UDP       BOOTP (BootStrap Protocol) server; also used by DHCP (Dynamic Host Configuration Protocol)

68           UDP       BOOTP (BootStrap Protocol) client; also used by DHCP (Dynamic Host Configuration Protocol)

69           UDP       TFTP (Trivial File Transfer Protocol)

70           TCP        Gopher protocol

79           TCP        Finger protocol

80           TCP        HTTP (HyperText Transfer Protocol) - used for transferring web pages

81           TCP        Torpark - Onion routing ORport

82           UDP       Torpark - Control Port

88           TCP        Kerberos - authenticating agent

101         TCP        HOSTNAME

102         TCP        ISO-TSAP protocol/Microsoft Exchange

107         TCP        Remote Telnet Service

109         TCP        POP, Post Office Protocol, version 2

110         TCP        POP3 (Post Office Protocol version 3) - used for retrieving emails

111         TCP, UDP             SUNRPC protocol

113         TCP        Ident - old server identification system, still used by IRC servers to identify its users

115         TCP        SFTP, Simple File Transfer Protocol

117         TCP        UUCP-PATH

118         TCP, UDP             SQL Services

119         TCP        NNTP (Network News Transfer Protocol) - used for retrieving newsgroups messages

123         UDP       NTP (Network Time Protocol) - used for time synchronization

135         TCP, UDP             EPMAP / Microsoft RPC Locator Service

137         TCP, UDP             NetBIOS NetBIOS Name Service

138         TCP, UDP             NetBIOS NetBIOS Datagram Service

139         TCP, UDP             NetBIOS NetBIOS Session Service

143         TCP, UDP             IMAP4 (Internet Message Access Protocol 4) - used for retrieving emails

152         TCP, UDP             BFTP, Background File Transfer Program

153         TCP, UDP             SGMP, Simple Gateway Monitoring Protocol

156         TCP, UDP             SQL Service

157         TCP, UDP             KNET VM Command Message Protocol

158         TCP, UDP             DMSP, Distributed Mail Service Protocol

159         TCP, UDP             NSS-Routing

160         TCP, UDP             SGMP-TRAPS

161         TCP, UDP             SNMP (Simple Network Management Protocol)

162         TCP, UDP             SNMPTRAP

170         TCP        Print-srv

179         TCP        BGP (Border Gateway Protocol) - an exterior gateway routing protocol that enables groups of routers to share routing information.

190         TCP, UDP             Gateway Access Control Protocol (GACP)

191         TCP, UDP             Prospero Directory Service

192         TCP, UDP             OSU Network Monitoring System, Apple AirPort Base Station PPP status or discovery, AirPort Admin Utility or Express Assistant

192         TCP. UDP             SRMP (Spider Remote Monitoring Protocol)

194         TCP        IRC (Internet Relay Chat)

201         TCP, UDP             AppleTalk Routing Maintenance

209         TCP, UDP             The Quick Mail Transfer Protocol

213         TCP, UDP             IPX

218         TCP, UDP             MPP, Message Posting Protocol

220         TCP, UDP             IMAP, Interactive Mail AccessProtocol, version 3

259         TCP, UDP             ESRO, Efficient Short Remote Operations

264         TCP, UDP             BGMP, Border Gateway Multicast Protocol

311         TCP        Apple Server-Admin-Tool, Workgroup-Manager-Tool

318         TCP, UDP             TSP, Time Stamp Protocol

323         TCP, UDP             IMMP, Internet Message Mapping Protocol

383         TCP, UDP             HP OpenView HTTPs Operations Agent

366         TCP, UDP             SMTP, Simple Mail Transfer Protocol. On-Demand Mail Relay (ODMR)

369         TCP, UDP             Rpc2portmap

371         TCP, UDP             ClearCase albd

384         TCP, UDP             A Remote Network Server System

387         TCP, UDP             AURP, AppleTalk Update-Based Routing Protocol

389         TCP, UDP             LDAP (Lightweight Directory Access Protocol)

401         TCP, UDP             UPS Uninterruptible Power Supply

411         TCP        Direct Connect Hub port

427         TCP, UDP             SLP (Service Location Protocol)

443         TCP        HTTPS - HTTP Protocol over TLS/SSL (used for transferring web pages securely using encryption)

444         TCP, UDP             SNPP, Simple Network Paging Protocol

445         TCP        Microsoft-DS (Active Directory, Windows shares, Sasser worm, Agobot, Zobotworm)

445         UDP       Microsoft-DS SMB file sharing

464         TCP, UDP             Kerberos Change/Set password

465         TCP        SMTP over SSL - CONFLICT with registered Cisco protocol

500         TCP, UDP             ISAKMP, IKE-Internet Key Exchange

512         TCP        exec, Remote Process Execution

512         UDP       comsat, together with biff: notifies users of new c.q. yet unread e-mail

513         TCP        Login

513         UDP       Who

514         TCP        rsh protocol - used to execute non-interactive commandline commands on a remote system and see the screen return

514         UDP       syslog protocol - used for system logging

515         TCP        Line Printer Daemon protocol - used in LPD printer servers

517         TCP        Talk

518         UDP       NTalk

520         TCP        efs

520         UDP       Routing - RIP

513         UDP       Router

524         TCP, UDP             NCP (NetWare Core Protocol) is used for a variety things such as access to primary NetWare server resources

525         UDP       Timed, Timeserver

530         TCP, UDP             RPC

531         TCP, UDP             AOL Instant Messenger, IRC

532         TCP        netnews

533         UDP       netwall, For Emergency Broadcasts

540         TCP        UUCP (Unix-to-Unix Copy Protocol)

542         TCP, UDP             commerce (Commerce Applications)

543         TCP        klogin, Kerberos login

544         TCP        kshell, Kerberos Remote Shell

546         TCP, UDP             DHCPv6 client

547         TCP, UDP             DHCPv6 server

548         TCP        AFP (Apple Filing Protocol)

550         UDP       new-rwho, new-who

554         TCP, UDP             RTSP (Real Time Streaming Protocol)

556         TCP        Remotefs, rfs, rfs_server

560         UDP       rmonitor, Remote Monitor

561         UDP       monitor

561         TCP, UDP             chcmd

563         TCP, UDP             NNTP protocol over TLS/SSL (NNTPS)

587         TCP        Email message submission (SMTP) (RFC 2476)

591         TCP        FileMaker 6.0 Web Sharing (HTTP Alternate, see port 80)

593         TCP, UDP             HTTP RPC Ep Map/Microsoft DCOM

604         TCP        TUNNEL

631         TCP, UDP             IPP, Internet Printing Protocol

636         TCP, UDP             LDAP over SSL (encrypted transmission)

639         TCP, UDP             MSDP, Multicast Source Discovery Protocol

646         TCP        LDP, Label Distribution Protocol

647         TCP        DHCP Failover Protocol

648         TCP        RRP, Registry Registrar Protocol

652         TCP        DTCP, Dynamic Tunnel Configuration Protocol

654         TCP        AODV, Ad hoc On-Demand Distance Vector

665         TCP        sun-dr, Remote Dynamic Reconfiguration

666         UDP       Doom, First online FPS

674         TCP        ACAP, Application Configuration Access Protocol

691         TCP        Microsoft Exchange Routing

692         TCP        Hyperwave-ISP

695         TCP        IEEE-MMS-SSL

698         TCP        OLSR, Optimized Link State Routing

699         TCP        Access Network

700         TCP        EPP, Extensible Provisioning Protocol

701         TCP        LMP, Link Management Protocol.

702         TCP        IRIS over BEEP

706         TCP        SILC, Secure Internet Live Conferencing

711         TCP        TDP, Tag Distribution Protocol

712         TCP        TBRPF, Topology Broadcast based on Reverse-Path Forwarding

720         TCP        SMQP, Simple Message Queue Protocol

749         TCP, UDP             kerberos-adm, Kerberos administration

750         UDP       Kerberos version IV

782         TCP        Conserver serial-console management server

829         TCP        CMP (Certificate Management Protocol)

860         TCP        iSCSI

873         TCP        rsync - File synchronisation protocol

901         TCP        Samba Web Administration Tool (SWAT)

902                         VMware Server

911         TCP        Network Console on Acid (NCA) - local tty redirection over OpenSSH

981         TCP        SofaWare Technologies Remote HTTPS management for firewall devices

989         TCP, UDP             FTP Protocol (data) over TLS/SSL

990         TCP, UDP             FTP Protocol (control) over TLS/SSL

991         TCP, UDP             NAS (Netnews Admin System)

992         TCP, UDP             Telnet protocol over TLS/SSL

993         TCP        IMAP4 over SSL (encrypted transmission)

995         TCP        POP3 over SSL (encrypted transmission)