Protocols & Ports Flashcards
What are ports?
Ports, allow various types of data to be sent and received by specific applications. Understanding how ports work is important because it allows you to control which types of data can enter and leave your network, as well as protect against unauthorized access.
What are port numbers?
Port numbers are used to identify different types of data during transmission and are assigned within the transport layer of both the TCP IP suite and the OSI model. This range of numbers goes from 0 to 65,535. Both the Transmission Control Protocol, or TCP, and User Datagram Protocol, or UDP, use port numbers to identify themselves. The application layer of both models identifies the specific protocol required by the application. And then the transport layer assigns a port number to that protocol, using a specific number to identify it. These port numbers are used to identify protocols, but also to keep track of data as it moves around devices on the network. Firewalls use port numbers all the time to permit and deny access to network.
Understanding how port numbers are used in network security is crucial. Firewalls rely on port numbers to permit or deny access to a network, but managing the range of port numbers is equally important to prevent unauthorized access.
What is a network protocol?
A network protocol is a set of conditions and rules that specify how network devices communicate on a given network. For example, when you use a web browser like Microsoft Edge to visit web pages, it uses protocols to deliver the data to the browser.
Protocols provide a standard framework for establishing and maintaining communication channels and for handling errors or faults should they occur. This allows communication between different network-enabled devices like laptops, tablets, smartphones, desktops, and servers, making network protocols essential building blocks for designing an organization’s network architecture.
Various types of applications and hardware devices depend on specific network protocols on a typical network. For example, browsing the internet using a web browser requires a different protocol than sending or receiving an email. Each protocol has unique properties that govern its use and implementation.
What are the 3 types of network protocol?
Network communication protocols
Network security protocols
Network management protocols
What are some common communication protocols?
Hypertext Transfer Protocol (HTTP): The HTTP protocol uses TCP/IP to deliver web page content from a server to your browser. HTTP can also handle the download and upload of files from remote servers.
File Transfer Protocol (FTP): FTP is used to transfer files between different computers on a network. Typically, FTP is used to upload files to a server from a remote location. While you can use FTP to download files, web-based downloads are typically handled through HTTP.
Post Office Protocol 3 (POP3): POP3 is one of three email protocols. It’s most commonly used by an email client to receive emails and it uses TCP to manage and deliver emails.
Simple Mail Transfer Protocol (SMTP): SMTP, another email protocol, is used to send emails from an email client via an email server and it uses the TCP for managing and transmitting emails.
Interactive Mail Access Protocol (IMAP): IMAP is the more powerful of the three email protocols. It lets you manage a single mailbox on an email server in your organization using an email client.
What is a network security protocol?
Network security protocols are designed to maintain the security and network of data across a network. Encryption is a key feature of network security protocols, which involves converting plain text into encoded, unreadable text to protect messages as they travel across the network. These protocols use encryption to secure messages and prevent unauthorized access or tampering.
What are the types of network security protocols?
Secure Socket Layer (SSL): SSL is a standard encryption and security protocol. It provides a secure and encrypted connection between your computer and the target server or device that you accessed over the internet.
Transport Layer Security (TLS): TLS is the successor to SSL and provides a stronger and more robust security encryption protocol. Based on the Internet Engineering Task Force (IETF) standard, it’s designed to stop message forgery and tampering and eavesdropping. It’s typically used to protect web browser communications, email, VoIP, and instant messaging. While TLS is now used, the replacement security protocol is often still called SSL.
Hypertext Transfer Protocol Secure (HTTPS): HTTPS provides a more secure version of the standard HTTP protocol by using the TLS or SSL encryption standard. This combination of protocols ensures that all data transmitted between the server and the web browser is encrypted and secure from eavesdropping or data packet sniffing. The same principle is applied to the POP, SMTP, and IMAP protocols listed previously to create secure versions known as POPS, SMTPS, and IMAPS.
Secure Shell (SSH): SSH is a cryptographic network security protocol that provides a secure data connection across a network. SSH is designed to support command-line execution of instructions, which includes remote authentication to servers. FTP uses many of the SSH functions to provide a secure file transfer mechanism.
What are network management protocols?
Network management protocols play a critical role in ensuring the smooth operation and sustainability of a network. Alongside communication and security protocols, they enable network administrators to monitor and manage devices and detect faults or performance issues.
What are the types of network management protocols?
Simple Network Management Protocol (SNMP): SNMP is an internet protocol that allows for the collection of data from devices on your network and the management of those devices. The device has to support SNMP to gather information. Devices that typically support SNMP include switches, routers, servers, laptops, desktops, and printers.
Internet Control Message Protocol (ICMP): ICMP is one of the protocols included within the Internet Protocol (IP) suite. It allows network-connected devices to send warning and error messages, along with operation information about the success or failure of a connection request, or if a service is unavailable. Unlike other network transport protocols like UDP and TCP, ICMP isn’t used to send or receive data from devices on the network.
What are port number ranges?
You now know that the range of port numbers used globally is from 0 to 65,535, which is a vast number range. The Internet Assigned Numbers Authority (IANA) manages these port numbers since they change over time as technology and protocols evolve. Any changes made to these port numbers require IANA’s permission.
What are the 3 well known port numbers?
Well-known ports (0 - 1,023) are reserved for specific protocols and services used by system processes and applications.
Registered ports (1,024 - 49,151) are assigned by IANA for specific services or protocols and can also be used by user applications.
Dynamic or private ports (49,152 - 65,535) are used by client applications to connect to servers and are assigned temporarily for the duration of a session.
What is a well known port number?
Well-known port numbers (0 - 1,023)
Well-known port numbers are reserved for some of the most commonly used and popular protocols in computer networks. These ports can either transfer verified data via TCP or unverified data via UDP. They are assigned at the transport layer of the OSI model or TCP/IP suite and identified at the application layer.
What is an alternative version for security protocol?
These alternative versions often involve encryption using a security protocol to enhance security. One such example is HTTPS, which uses the Transport Layer Security (TLS) protocol to encrypt data as it moves across the network. TLS is also used in other protocols to improve their security, with the letter ‘S’ added to the end of the original protocol name to signify the use of TLS.
What are registered ports?
Registered ports (1,024 - 49,151)
Registered ports are assigned by IANA to companies for specific services that they want to use. These ports are often used in the gaming sector to identify the ports that need to be opened in home networks to allow games to function.
Examples include port 3074 for the XBOX live network or ports 3,479/80 for the PlayStation network. These ports have changed as games become less relevant and new ones emerge on the market. As technology changes, new ports are assigned and old ones are retired. Some registered ports have been around for a while, such as SIP and H323 which are video conferencing protocols that use port numbers 1,719, 1,720, 5,060, and 5,061. For SIP, port 5,060 is used for unencrypted data, while port 5,061 is used for encrypted data.
What are dynamic ports?
Dynamic or private ports (49,152 - 65,535)
Dynamic or private ports are essential for communication between protocols using TCP or UDP. When a computer has multiple web pages open simultaneously, dynamic ports are used to identify different sessions. Each open web page will be associated with a different port number, which serves as the source port number for communication between devices. This is crucial because it allows your computer to determine which data belongs to which web page, and it is also the number used for devices to communicate responses
