Networking

• What is UDP

  UDP, or User Datagram Protocol, is one of the core transport layer protocols in the Internet Protocol (IP) suite, alongside TCP (Transmission Control Protocol). UDP provides a connectionless and lightweight method for sending data between devices over a network.
• What is TCP?

  TCP, which stands for Transmission Control Protocol, is one of the core transport layer protocols in the Internet Protocol (IP) suite. TCP is responsible for providing reliable, connection-oriented communication between devices over a network.
• What is FTP and its port number?

  - 21

  
  

  tcp/20 (active mode data)

  tcp/21 (control)

  
  

  FTP, or File Transfer Protocol, is a standard network protocol used for transferring files between a client and a server over a computer network, such as the internet or a local area network (LAN). FTP is designed for efficient and reliable file transfer and management.
• What is SSH and its port number?

  - 22

  
  

  SSH, which stands for Secure Shell, is a cryptographic network protocol used for secure remote access and secure data communication over a potentially unsecured network. It is commonly used in both UNIX-like and Windows operating systems. SSH provides a secure and encrypted means of connecting to remote servers and devices.
• What is Telnet and its port number?

  - 23

  
  

  Telnet, short for "teletype network," is a network protocol used for remote terminal access to devices and systems over a network, typically the internet or a local area network (LAN). It allows a user to establish a text-based terminal session with a remote device or server, enabling them to issue commands and interact with the remote system as if they were physically present at the terminal.
• What is SMTP and its port number?

  - 25

  
  

  SMTP, or Simple Mail Transfer Protocol, is a widely used network protocol for sending and relaying email messages over the Internet. SMTP is essential for the transmission of email from a sender's email client or server to a recipient's email server.
• What is DNS and its port number?

  - 53

  
  

  DNS, which stands for Domain Name System, is a hierarchical and distributed naming system used to translate human-friendly domain names into numeric IP addresses and vice versa. DNS plays a fundamental role in enabling users to access websites, send emails, and communicate over the internet.
• What is HTTP and its port number?

  - 80

  
  

  HTTP, or Hypertext Transfer Protocol, is an application-layer protocol used for transmitting and receiving data on the World Wide Web. HTTP is the foundation of data communication on the internet and serves as the basis for the transfer of web pages, images, videos, and other web resources between clients (typically web browsers) and web servers.
• What is POP3 and its port number?

  - 110

  
  

  POP3, which stands for Post Office Protocol version 3, is an internet standard protocol used for receiving and downloading email messages from a remote email server to a local email client. POP3 is one of the most common email retrieval protocols and is widely used for accessing and managing email messages.
• What is IMAP and its port number?

  - 143

  
  

  IMAP, which stands for Internet Message Access Protocol, is an email retrieval and storage protocol used by email clients to access and manage email messages stored on a remote email server. IMAP is an alternative to POP3 (Post Office Protocol version 3) and offers more advanced features for email management and synchronization.
• What is HTTPS and its port number?

  - 443

  
  

  HTTPS, which stands for Hypertext Transfer Protocol Secure, is an extension of the HTTP protocol used for secure communication over a computer network, typically the internet. HTTPS ensures that the data exchanged between a web browser or client and a web server is encrypted and secure.
• What is RDP and its port number?

  - 3389

  
  

  RDP, or Remote Desktop Protocol, is a proprietary protocol developed by Microsoft for the purpose of remote desktop access and remote control of Windows-based computers or servers over a network. RDP allows users to connect to a remote Windows system and interact with its desktop environment as if they were physically present at the remote machine.
• What is NetBIOS/NetBT and its port number?

  - 137

  NetBIOS, which stands for Network Basic Input/Output System, is a legacy networking protocol used in early Windows-based operating systems and some other systems for communication within local area networks (LANs). NetBIOS provides a set of services and protocols for tasks such as naming, browsing, and sharing resources on a network. While it is considered outdated, knowledge of NetBIOS may be relevant for historical context and troubleshooting older network configurations.

  
  

  
  

  -139

  NetBT, which stands for NetBIOS over TCP/IP, is a networking protocol that extends the functionality of NetBIOS (Network Basic Input/Output System) by allowing NetBIOS traffic to be transmitted over TCP/IP networks. NetBT enables the use of NetBIOS services and name resolution within TCP/IP-based networks
• What is SMB/CIFS and its port number?

  - 445

  
  

  SMB (Server Message Block) and CIFS (Common Internet File System) are network file-sharing protocols used for sharing files, folders, printers, and other resources between computers on a network, particularly in Windows-based environments. These protocols enable seamless file sharing and resource access across different operating systems.
• What is AFP and its port number?

  - 548

  
  

  AFP, which stands for Apple Filing Protocol, is a proprietary network protocol developed by Apple Inc. for sharing files, directories, and resources over a network. AFP is primarily used in Apple's macOS and macOS Server environments to provide file sharing and access control features.
• What is SLP and its port number?

  - 445

  
  

  SLP, which stands for Service Location Protocol, is a networking protocol used for service discovery and advertisement within local area networks (LANs) and other IP-based networks. SLP enables devices and services to automatically discover and announce their availability on the network, making it easier for users and applications to locate and use network resources.
• What is DHCP and its port number?

  - 67/68

  
  

  DHCP, which stands for Dynamic Host Configuration Protocol, is a network protocol used to automatically assign IP addresses and other network configuration settings to devices on a TCP/IP network. DHCP simplifies network administration by automating the process of configuring network parameters for devices as they connect to the network.
• What is LDAP and its port number?

  - 389

  
  

  LDAP, which stands for Lightweight Directory Access Protocol, is a protocol used for accessing and managing directory services over a network. Directory services are databases that store information about network resources, such as users, groups, devices, and other objects. LDAP provides a standardized way to query, retrieve, and update information in these directories.
• What is SNMP and its port number?

  - 161/162

  
  

  SNMP, which stands for Simple Network Management Protocol, is a widely used network protocol for managing and monitoring network-connected devices and systems. SNMP allows network administrators to collect information, set configurations, and receive notifications from network devices, such as routers, switches, servers, and printers
• Give an analogy to remember the concept of IP address and Port Numbers


  In an apartment building, the IP address is the apartment number and the port is the room number inside the apartment.
• What is a router?

  A router is a network device that plays a critical role in directing data packets between different networks. It operates at the network layer (Layer 3) of the OSI model and is commonly used in home networks, businesses, and the global internet to connect and manage data traffic.
• What is a switch?


  A switch is a network device commonly used in local area networks (LANs) to connect and manage the traffic between devices, such as computers, printers, servers, and other networked devices. Switches operate at the data link layer (Layer 2) of the OSI model and play a crucial role in efficiently forwarding data packets within a network. Decides where data should be forwarded based off of the destination MAC address.
• What is an unmanaged switch?


  n unmanaged switch is a basic network switch that operates at the data link layer (Layer 2) of the OSI model. Unlike managed switches, unmanaged switches are designed for simplicity and ease of use, making them ideal for small networks and home environments.

  
  

  - plug and play

  - No VLANs

  - No managed protocols

  - basic forwarding
• What is a managed switch


  A managed switch is a network switch that offers advanced configuration and management features beyond what is provided by unmanaged switches. Managed switches are commonly used in business and enterprise environments where network administrators require greater control, security, and visibility into the network.

  
  

  - Supports VLAN

  - Spanning Tree Protocol

  - Port mirroring
• What is an access point?


  An access point (AP) is a networking hardware device that allows Wi-Fi-enabled devices, such as smartphones, laptops, tablets, and other wireless clients, to connect to a wired network. Access points are commonly used in wireless local area networks (WLANs) to extend network connectivity and provide wireless access to users.

  
  

  -Not a wireless router

  - a bridge between wireless user and wired network

  - makes forwarding decisions based off the MAC address
• What is a firewall?

  A firewall is a network security device or software application that acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. Its primary purpose is to monitor and control incoming and outgoing network traffic, allowing or blocking data packets based on predefined security rules and policies.

  
  

  - filters traffis

  - acan encrypt traffic

  - can proxy traffic
• What is PoE?


  PoE stands for "Power over Ethernet," and it is a technology that allows electrical power to be transmitted over Ethernet cables alongside data signals. PoE is commonly used in networking and telecommunications to power devices like IP phones, security cameras, wireless access points, and other networked equipment.
• What is a modem?

  A modem, short for "modulator-demodulator," is a fundamental networking device that plays a crucial role in connecting computers and other digital devices to the internet. It facilitates the transmission of data between these devices and the internet service provider (ISP)
• What is a hub?


  A hub is a basic networking device that operates at the physical layer (Layer 1) of the OSI model. It is used to connect multiple network devices, such as computers and printers, within a local area network (LAN). However, hubs are relatively simple and have been largely replaced by more advanced network devices like switches.

  
  

  - No MAC address table

  - More of a legacy device
• What is SDN?


  SDN, or Software-Defined Networking, is a networking approach that uses software-based controllers and application programming interfaces (APIs) to dynamically control and manage network infrastructure. SDN decouples the control plane (which manages network traffic and makes routing decisions) from the data plane (which handles the forwarding of data packets) to enable more flexible, agile, and programmable network management.
• What is 802.11a


  IEEE 802.11a is one of the earlier standards in the 802.11 family, defining a set of specifications for wireless local area networks (WLANs). It operates in the 5 GHz frequency band and offers certain advantages over earlier 802.11 standards, such as 802.11b.

  
  

  - Operates at 54 megabits per second

  - Not comonly used today
• What is 802.11b


  IEEE 802.11b is one of the early standards in the 802.11 family, defining specifications for wireless local area networks (WLANs). It operates in the 2.4 GHz frequency band and was a significant advancement in wireless networking technology at the time.

  
  

  - Operates at 11 megabits per second

  - Not an upgrade to 802.11a

  - Not commonly seen today
• What is 802.11g


  IEEE 802.11g is a wireless networking standard within the 802.11 family, defining specifications for wireless local area networks (WLANs). It operates in the 2.4 GHz frequency band and offered significant improvements over earlier standards like 802.11b.

  
  

  - An upgrade from 802.11b
• What is 802.11n


  IEEE 802.11n, often simply referred to as "802.11n" or "Wi-Fi 4," is a wireless networking standard within the 802.11 family. It introduced significant improvements in data rates, range, and overall performance compared to earlier Wi-Fi standards.

  
  

  - also called Wifi 4

  -
• What is 802.11ac


  IEEE 802.11ac, often referred to as "802.11ac" or "Wi-Fi 5," is a wireless networking standard within the 802.11 family. It brought significant improvements in data rates, network capacity, and overall performance compared to earlier Wi-Fi standards.

  
  

  - also called wifi 5

  - operates in the 5 GHz band
• What are frequencies?


  Frequencies in the context of networking and wireless communication refer to the specific electromagnetic wave frequencies used to transmit data and signals. These frequencies are typically measured in Hertz (Hz) and are part of the electromagnetic spectrum.

  
  

  - 2.4 GHz. The 2.4 GHz band is widely used for wireless communication, including 802.11b, 802.11g, and 802.11n Wi-Fi standards. It's also used for Bluetooth and many other wireless technologies. However, it can be susceptible to interference from other devices in the same frequency range.

  
  

  - 5GHz. The 5 GHz band is less crowded and offers more available channels compared to the 2.4 GHz band. It's commonly used in newer Wi-Fi standards like 802.11a, 802.11ac, and 802.11ax (Wi-Fi 6).
• What is 802.11ax?


  IEEE 802.11ax, often referred to as "802.11ax" or "Wi-Fi 6," is a wireless networking standard within the 802.11 family. It represents a significant advancement in Wi-Fi technology, introducing improvements in data rates, capacity, and efficiency.

  
  

  - 5 GHz

  - 1,201 megabits p/s
• What is RFID?


  Radio Frequency Identification
• What is NFC?


  Near Field Communication

  
  

  - Online wallets

  - Touch and go credit card
• What is DNS?


  DNS, which stands for Domain Name System, is a critical component of the internet's infrastructure that converts human-readable domain names into IP addresses. This system makes it possible for users to access websites and other online resources using easy-to-remember domain names instead of having to remember numerical IP addresses.