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- A collection of interconnected devices that share resources and communicate using standard protocols.
OSI model
- A framework that divides networking into 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
TCP vs UDP
- TCP is reliable and connection-oriented. UDP is faster, connectionless, and less reliable.
IP Address
- A unique identifier for devices on a network, used for routing data between them.
IPv4 vs IPv6
- IPv4: 32-bit, supports 4.3 billion devices. IPv6: 128-bit, supports a vastly larger number of devices.
MAC Address
- A unique hardware identifier for network devices used at the Data Link Layer.
DNS (Domain Name System)
- Translates domain names (e.g., google.com) into IP addresses for communication.
DHCP (Dynamic Host Configuration Protocol)
- Automatically assigns IP addresses to devices in a network, simplifying management.
Subnet Mask
- Defines the network and host portions of an IP address, aiding in efficient IP address allocation.
Router vs Switch
- Router: Connects multiple networks and routes data between them.
- Switch: Connects devices within a network, forwarding data based on MAC addresses.
Hub vs Switch
- Hub: Broadcasts data to all devices.
- Switch: Directs data to the intended recipient.
Firewall
- Controls incoming and outgoing network traffic based on security rules, protecting against unauthorized access.
NAT (Network Address Translation)
- Translates private IP addresses to a public one, allowing multiple devices to share a single public IP.
Static vs Dynamic IP Addressing
- Static: Manually assigned and permanent.
- Dynamic: Automatically assigned via DHCP and can change over time.
VPN (Virtual Private Network)
- Creates an encrypted tunnel for secure communication over a public network like the internet.
Three-Way Handshake (TCP)
- Used to establish a TCP connection: SYN, SYN-ACK, and ACK packets are exchanged to confirm readiness.
Proxy Server
- Acts as an intermediary between client and server, often used for security, caching, and anonymity.
ARP (Address Resolution Protocol)
- Resolves IP addresses to MAC addresses, enabling devices to communicate on a local network.
Latency
- The delay between sending and receiving data, measured in milliseconds (ms).
Bandwidth
- The maximum rate of data transfer across a network, measured in bits per second (bps).
Throughput
- The actual rate of successful data transfer, often lower than bandwidth due to network conditions.
Packet Loss
- Occurs when one or more packets fail to reach their destination due to network issues.
VLAN (Virtual Local Area Network)
- A logical grouping of devices within a network, improving segmentation and security.
Socket
- An endpoint for communication, identified by an IP address and port number, facilitating data transfer between devices.
Port Forwarding
- Maps external traffic to a specific internal IP and port, allowing access to services on a private network.
Load Balancer
- Distributes traffic across multiple servers to enhance performance and reliability.
ICMP (Internet Control Message Protocol)
- Used for error reporting and diagnostic functions like
ping
to check connectivity.
Traceroute
- A tool that shows the path packets take from one device to another, used for troubleshooting network issues.
SSL/TLS
- Security protocols that encrypt data sent over the internet, ensuring secure communication.
CDN (Content Delivery Network)
- A network of distributed servers that deliver web content from locations closer to users for faster access.
QoS (Quality of Service)
- Techniques to prioritize certain types of traffic (e.g., VoIP) to ensure high performance for critical applications.
Collision Domain vs Broadcast Domain
- Collision Domain: A network segment where data collisions can occur.
- Broadcast Domain: A network segment where broadcast traffic is received by all devices.
BGP (Border Gateway Protocol)
- A protocol used to exchange routing information between different networks on the internet.
DNS Server
- Resolves domain names into IP addresses, enabling access to websites via human-readable names.
Half-Duplex vs Full-Duplex
- Half-Duplex: Data flows in one direction at a time.
- Full-Duplex: Data flows in both directions simultaneously.
Multicast
- Sends data to multiple devices in a group, more efficient than sending individual unicast messages.
Internet vs Intranet
- Internet: Global public network.
- Intranet: Private network within an organization.
Strongly Connected Components in Graph
- A component of a directed graph where every vertex is reachable from every other vertex in that component.
Bridges in Graph
- A bridge is an edge in a graph, whose removal increases the number of connected components in the graph.
Traceroute and Ping Difference
- Ping: Measures the round-trip time for packets.
- Traceroute: Shows the path packets take between devices, useful for troubleshooting.