CompTIA Network + Ports & Protocols

Port

Virtual entry/exit point for communications used by software applications to exchange information

Protocol

Set of rules and conventions for data exchange between network devices

Port

A logical opening in a computer that represents a service or application

Ephemeral Ports

Short-lived temporary ports which are opened for just a small period of time from a predefined range of ports

Transmission Control Protocol (TCP)

A fundamental protocol within the internet protocol suite that consists of set of rules that govern the exchange of data

Windowing

Occurs by allowing the receiver to specify the amount of data it can handle at a time

Port

A numerical identifier in TCP/IP and other network protocols that helps distinguish between different services or applications

User Datagram Protocol (UDP)

A communication protocol used across the Internet for especially time-sensitive transmissions

Internet Control Message Protocol (ICMP)

Integral part of the Internet Protocol Suite which is a set of networking protocols used on the Internet

ICMP Flood Attack

Type of attack that involves overwhelming a target machine with a large number of ICMP Echo Request packets

Distributed Denial of Service (DDos) Attack

Where the attacker usually uses a network of compromised computers (called a botnet) to generate a significant amount of traffic

Ping of Death

Attack that exploits a vulnerability that existed in older, unpatched systems where the attacker sends malformed or oversized packets using the ICMP protocol

Hypertext Transfer Protocol (HTTP)

An application Layer protocol that enables plain text communication between clients and servers (Port 80)

Hypertext Transfer Protocol Secure (HTTPS)

HTTP with encryption on the data being transferred over the network (Port 443)

Simple Mail Transfer Protocol (SMTP)

Standard protocol used for sending emails across the Internet and operates over Port 25

Simple Mail Transfer Protocol Secure (SMTPS)

Not a protocol itself, but a way for SMTP to be sent secure using SSL or TLS Tunnel (Port 465 or 587)

Post Office Protocol Version 3 (POP3)

Used to retrieve emails from a remote server to a local client over Port 110

Post Office Protocol Version 3 Secure (POP3 Secure)

Was introduced to overcome the limitations of POP3

Internet Message Access Protocol (IMAP)

Operates over Port 143 and allows users to manage emails directly on the email server

IMAPS (IMAP Secure)

Operates over port 993

File Transfer Ports and Protocols

Specialized rules and procedures that are utilized for the transmission of files across networks, operate on the designated ports, and act as doorways for data transfer activities

File Transfer Protocol (FTP)

Used for transferring files between a client and a server over a network (Port 20 & Port 21)

Secure File Transfer Protocol (SFTP)/SSH File Transfer Protocol (Secure FTP)

Created to address the security concerns of FTP and operates over port 22

Trivial File Transfer Protocol (TFTP)

Simpler and more basic version of the FTP and operates over port 69

Server Message Block (SMB)

Operates over port 445 and allows computer apps to read and write to files and request services from the server programs.

Secure Shell (SSH)

Protocol used for secure remote login and other secure network services over an unsecure network (Port 22)

Telnet

Allows a user on one computer to login remotely to another computer (Port 23)

Remote Desktop Protocol (RDP)

Proprietary protocol that was developed by Microsoft to provide users with a graphical user interface to connect to another computer over a network connection (Port 3389)

Network Service Ports and Protocols

Different services that ensure that network devices can discover each other, communicate efficiently, and relay important system information to each other

Domain Name System (DNS)

Used to translate human-friendly domain names into an IP address that computers can use to identify each other on a network (Port 53)

Dynamic Host Configuration Protocol (DHCP)

Used to automate the assignment of IP addresses, subnets, mass gateways and other networking parameters to a client device (DHCP servers listen for client requests over port 67, and the clients will receive responses back over port 68 using UDP)

SQL Services

Protocols used by database servers to manage queries and control operations from the client applications that are requesting them. (Microsoft SQL Port 1433 & MySQL Port 3306)

Simple Network Management Protocol (SNMP)

Used for collecting information from and configuring different network devices like servers, printers, hubs, switches, and routers over an IP network. (Ports 161 & 162 using the user datagram protocol)

System Logging (Syslog)

Standard for message logging that allows devices to send event messages across IP networks to an event message collector known as a Syslog server. (Port 514 using UDP or TCP)

Network Time Protocol (NTP)

Used to synchronize the clocks of a computer over a given network ( Port 23 using the user datagram protocol)

Session Initiation Protocol (SIP)

Used for initiating, maintaining, and terminating real-time sessions that involve voice, video messaging, and other communication services (Port 5060 on UDP & TCP and Port 5061 using TCP)

Lightweight Directory Access Protocol (LDAP)

Protocol for accessing and maintaining distributed directory information services over an IP network (LDAP operates over port 389 using both TCP and UDP)

LDAP over SSL (LDAPS)

Version of LDAP that is encrypted with SSL or, in newer versions, TLS for increased security (Operates over port 636using TCP)