Ports and Protocols

A list of common ports and protocols with their applications and encrypted alternatives

20 | 21 - File Transfer Protocol (FTP)

Transfers computer files between a client and server on a computer network

Unsecure since data is tranferred in the clear

Port 20 used to transfer data

Port 21 used to establish connection

22 - Secure Shell (SSH) | Secure FTP (SFTP)

Cryptographic network protocol for operating network services securely

Best known for remote login to computer systems by users

SFTP provides file access, file transfer, and file management over any data stream

23 - Telnet

Provides bidirectional interactive text-oriented communication facility

Unsecure version of SSH

25 - Simple Mail Transfer Protocol (SMTP)

Internet standard for sending electronic mail

RFC 821 was defined originally in 1982

RFC 5321 developed in 2008 (current version)

53 - Domain Name System (DNS)

Hierarchical decentralized naming system for computers, services, or other resources

Converts domain names to IP adddresses

67 | 68 - Dynamic Host Configuration Protocol (DHCP)

DHCP server dynamically assigns an IP address and other network configurations

Enables computers to request IP addresses and networking parameters

Port UDP 67 is for server

Port UDP 68 is for client

69 - Trivial File Transfer Protocol (TFTP)

Transmits files in both directions of a client-server application

Used for booting an OS from a LAN file server

Essentially a stripped down version of FTP - no authentication of directory visibility

80 - Hypertext Transfer Protocol

Foundation of data communication for WWW

Designed for distributive, collaborative, and hypermedia presentation across devices

110 - Post Office Protocol v3 (POP3)

Used by local e-mail clients to download e-mails from a remote server over TCP/IP

112 - Virtual Router Redundancy Protocol (VRRP)

Used for automatic assignment of available IP routers to particpating hosts in order to increase availability and reliability of routing paths via default gateway

123 - Network Time Protocol (NTP)

Provides clock synchronization between computer sustems over packet-switched, variable-latency data networks, created in 1985, one of the olderst protocols in use

139 - Server Message Block (SMB) [Over NetBIOS]

Network Basic Input/Output System (NetBIOS)

Provides services allowing applications on separate computers to communicate over a LAN for file and printer sharing

143 - Internet Message Access Protocol (IMAP)

Provides e-mail clients to remotely view e-mail messages from a mail server over TCP/IP

Allows the end user to view and manipulate the messages as if they're locally stored

161 | 162 - Simple Network Management Protocol (SNMP)

Provides collection and organization of information about managed devices

Can modify information to change device behavior, commonly used in network devices

Port UDP 161 is for SNMP managers communicating with SNMP agents

Port UDP 162 is used for unsolicited traps sent from agents to the manager

SNMPv3 > "authPriv" ensures authentication and privacy

389 - Lightweight Directory Access Protocol (LDAP)

Open, vendor-neutral, industry standard for accessing and maintaining distributed directory information services

LDAP and Active Directory use this port

443 - Hypertext Transfer Protocol Secure (HTTPS)

Secure Sockets Layer (SSL)

Transport Layer Security (SSL)

Designed for adding security to the insecure HTTP protocol

445 - Server Message Block (SMB) [Over TCP Stack]

Later versions of SMB (after Windows 2000) use a TCP stack, allows Internet use

Provides shared access to files, printers, and misc. communications

514 - Syslog

System Logging Protocol - Used to send logging data to a centralized server

587 - SMTP TLS

Secure and encrypted way to send emails

636 - Lightweight Directory Access Protocol SSL (LDAPS)

Open, vendor-neutral, industry standard for accessing and maintaining distributed directory information services - provides secure directory services with SSL

993 - IMAP over SSL

Secure and encrypted way to receive emails over IMAP

995 - POP3 over SSL

Secure and encrypted way to receive emails over POP3

1433 - Microsoft SQL Database Server

Used for communication from a client to the database engine

1521 - SQLnet

Used for communication from a client to an Oracle database

1381 - RADIUS

Open-source networking protocol that provides Authentication, Authorization, and Accounting (AAAA) for users who connect and use a network service

3306 - MySQL

Used for communication from a client to the MySQL database engine

3389 - Remote Desktop Protocol (RDP)

Proprietary protocol developed by Microsoft

Provides a user with a graphical interface to connect to another computer

User employs RDP client software and target must run RDP server software

5060 | 5061 - Session Initiation Protocol (SIP)

Provides signaling and controlling multimedia communication sessions in apps

Used for Internet telephony for voice and video calls, VOIP, and instant messaging

Port 5060 is commonly used for non-encrypted signaling traffic

Port 5061 is typically used for traffic encrypted with Transport Layer Security (TLS)

5800 | 5900 - Virtual Network Computing (VNC)

Cross-platform screen sharing system that was crated to remotely control another computer from a distance by a remote user from a secondary device