Ports and Protocols

Inbound port

Logical communication opening on a server that is listening for a connection from a client

Outbound port

Logical communication created on a client to call out to a server that is listening

Registered Ports

Ports 1024-49151

Well-known ports

Ports 0-1023

Dynamic/Private Ports

Ports 49,152 - 65,535 that can be used by any application without being registered with IANA.

Port 21

• FTP

• TCP

• Used to transfer files from host to host

Port 22

• SSH, SCP, SFTP

• TCP

• Secure remote, copy and file transfers

Port 23

• Telnet

• TCP

• Insecure remote control

Port 25

• SMTP

• TCP

• Sends emails over the network

Port 53

• DNS

• TCP & UDP

• Translates name to IP

Port 69

• Trivial FTP

• UDP

• Lightweight ftp for sending config files or networking booting of an OS.

Port 80

• HTTP

• TCP

• Unsecure web browsing

88

• Kerberos

• UDP

• Network Auth protocol

110

• POP3

• TCP

• Retrieve email from server, download to local device and remove from server

119

• Network News Transfer Protocol (NNTP)

• TCP

• Used for accessing news groups

135

• Remote Procedure Call (RPC)

• TCP & UDP

• Communication between different system processes

143

• IMAP

• TCP

• Retrieves email and stores it on the server.

161

• SNMP

• Manages network devices

• UDP

162

• SNMP Traps

• UDP

• Sends traps which are unrequested notifications of an SNMP agent to central SNMP.

389

• LDAP

• TCP

• Directory services

445

• SMB

• Used for file and printer sharing over network

• TCP

465 and 587

• SMTP Secure

• TCP

• Encrypted SMTP using SSL/TLS

514

• syslog

• UDP

• Sends log messages

636

• LDAPS

• TCP

• Secure LDAP using SSL/TLS

995

• POP3S

• TCP

• SSL/TLS POP3

1433

• MS SQL

• TCP

• MS SQL Server

1645 & 1646

• RADIUS TCP

• Used for remote AAA

1812 & 1813

• RADIUS UDP

• Used for authentication and accounting by IETF

3389

• RDP

• TCP

• Remote desktop

6514

• Syslog TLS

• TCP

• SSL/TLS syslog

993

• IMAPS

• TCP

• TLS/SSL version of IMAP

137, 138 and 139

• NetBIOS

• TCP & UDP

• Network protocol suite used in Windows domain environments to share things like internal network names, as well as file and printer sharing.

Port 21 (FTP) - Which transport protocol does it use?

TCP

Port 22 (SSH, SCP, SFTP) - Which transport protocol does it use?

TCP

Port 23 (Telnet) - Which transport protocol does it use?

TCP

Port 25 (SMTP) - Which transport protocol does it use?

TCP

Port 53 (DNS) - Which transport protocol does it use?

TCP/UDP

Port 69 (Trivial FTP) - Which transport protocol does it use?

UDP

Port 80 (HTTP) - Which transport protocol does it use?

TCP

Port 88 (Kerberos) - Which transport protocol does it use?

UDP

Port 110 (POP3) - Which transport protocol does it use?

TCP

Port 119 (NNTP) - Which transport protocol does it use?

TCP

Port 135 (RPC) - Which transport protocol does it use?

TCP/UDP

Ports 137, 138, and 139 (NetBIOS) - Which transport protocol do they use?

TCP/UDP

Port 143 (IMAP) - Which transport protocol does it use?

TCP

Port 161 (SNMP) - Which transport protocol does it use?

UDP

Port 162 (SNMP Traps) - Which transport protocol does it use?

UDP

Port 389 (LDAP) - Which transport protocol does it use?

TCP

Port 445 (SMB) - Which transport protocol does it use?

TCP

Ports 465 and 587 (SMTP Secure) - Which transport protocol do they use?

TCP

Port 514 (Syslog) - Which transport protocol does it use?

UDP

Port 636 (LDAPS) - Which transport protocol does it use?

TCP

Port 993 (IMAPS) - Which transport protocol does it use?

TCP

Port 995 (POP3S) - Which transport protocol does it use?

TCP

Port 1433 (MS SQL) - Which transport protocol does it use?

TCP

Ports 1645 & 1646 (Legacy RADIUS) - Which transport protocol do they use?

TCP

Ports 1812 & 1813 (RADIUS) - Which transport protocol do they use?

UDP

Port 3389 (RDP) - Which transport protocol does it use?

TCP

Port 6514 (Syslog TLS) - Which transport protocol does it use?

TCP