Learn
Networking Fundamentals
How networks name devices, move data, and describe performance. Start here if addresses, models, and data units are still fuzzy.
- Explain the OSI and TCP/IP models without memorizing them as empty lists
- Read an IPv4 address, mask, and gateway as a set
- Tell packets, frames, TCP, and UDP apart
Use the stack to name where a problem lives. A real message is not handed between seven separate products.
Models
- Encapsulation
Wrapping data with the headers each network layer needs.
- OSI Model
A seven-layer reference model for describing network communication.
- TCP/IP Model
The four-layer model commonly used to describe Internet communication.
Addressing
- APIPA
A self-assigned 169.254 address used when no configuration server answers.
- CIDR
Slash notation that states how many bits belong to the network prefix.
- Default Gateway
The router a host uses for destinations outside its own subnet.
- IP Address
A numeric label that identifies a network interface for delivery.
- IPv4
The 32-bit Internet Protocol, usually written as four dotted decimals.
- IPv6
The 128-bit Internet Protocol, written in hexadecimal groups.
- Loopback Address
An address that delivers traffic to the same host, such as 127.0.0.1.
- MAC Address
A hardware address used to deliver frames on a local link.
- NAT
Rewriting addresses as packets cross between networks.
- Private IP Address
An address reserved for internal networks, not public Internet routing.
- Public IP Address
A globally routable address used on the public Internet.
- Subnet Mask
The value that splits an address into network and host portions.
- Subnetting
Splitting one network prefix into smaller network prefixes.
Switching
- VLAN
A logical split that puts switch ports into separate broadcast domains.
Forwarding
- Broadcast Domain
The group of interfaces that all receive the same broadcast.
- Collision Domain
A network section where two transmissions can interfere with each other.
- Routing
Forwarding packets from one network toward another using a route table.
- Switching
Forwarding local frames to the specific port that reaches the destination.
Transport
- TCP
A reliable, ordered transport protocol that retransmits lost data.
- Three-Way Handshake
The SYN, SYN-ACK, and ACK exchange that starts a reliable connection.
- UDP
A connectionless transport protocol that does not retransmit lost datagrams.
Data units
Performance
- Bandwidth
The maximum data-carrying capacity of a link over time.
- Jitter
Variation in packet delay that disrupts real-time audio and video.
- Latency
The delay before data arrives, often measured as round-trip time.
- Throughput
The amount of data actually transferred, not the advertised capacity.
Design
- Network Topology
The physical or logical arrangement of links and nodes.
Resolution
- ARP
Resolves a local 32-bit address to a hardware address.
Delivery
Name services
- DNS
The directory that translates names into addresses and other records.
Address configuration
- DHCP
Leases addresses and basic network settings to clients automatically.