Networking Terminology

Network:

a group of connected devices that can communicate

Node:

any device connected to a network

IP Address:

a unique numerical address assigned to a device

MAC Address:

a unique physical address assigned to a network interface it is used to identify devices within a network segment

Subnet Mask:

defines the network and host portions of an IP address

Default Gateway:

the node that forwards traffic to other networks

Domain Name System (DNS):

translates domain names to IP addresses

Dynamic Host Configuration Protocol (DHCP):

automatically assigns IP addresses

Router:

a device that forwards data between different networks

Switch:

a device that connects devices within the same network

Hub:

a basic device that connects multiple devices in a network

Firewall:

a security system that monitors and controls network traffic

Protocol:

a set of rules that govern data communication

Transmission Control Protocol (TCP):

ensures reliable data transmission

User Datagram Protocol (UDP):

a connectionless protocol for faster transmission

Port:

a logical endpoint used for communication in a network

Local Area Network (LAN):

a network within a limited area

Wide Area Network (WAN):

a network that spans larger geographical areas

Virtual Private Network (VPN):

a secure connection over the internet

Bandwidth:

the maximum data transfer rate of a network

Latency:

the delay before data begins to transfer

Packet:

a unit of data transmitted over a network

Service Set Identifier (SSID):

the name of a Wi-Fi network

Access Point:

a device that provides wireless network access

Topology:

the physical or logical layout of a network

Address Resolution Protocol (ARP):

connects a logical IP address to physical MAC address on a local area network (LAN)

Ipconfig:

show network configuration

ipconfig/all:

show detailed IP information

ipconfig/release:

release IP address

ipconfig/renew:

renew IP address

ipconfig/flushdns:

clear DNS cache

Ping [IP]:

check network connectivity

Tracert [IP]:

trace route to a destination

Nslookup [domain]:

query DNS for domain details

Netstat -an:

show active network connections

Arp -a:

show ARP cache

Hostname:

display computer name

Getmac:

show MAC address of network adapters

Net share:

list shared resources

Net start/stop:

stop a windows service

Netsh:

configure network settings

Application:

acts as the direct interface between software programs and the network. This layer provides network services for user actions like web browsing, email, and file transfers

DNS (53):

converts domain names to IP addresses

DHCP (67/68):

automatically assigns IP addresses

HTTP (80):

unencrypted web traffic

HTTPS (443):

secure encrypted web traffic

SMTP (25):

sending email

POP3 (110):

receiving email

IMAP (143):

email synchronization

SNMP (161/162):

network monitoring and management

NTP (123):

time synchronization

SSH (22):

secure remote access

FTP (21):

file transfer

SFTP (22):

secure file transfer

TFTP (69):

lightweight file transfer

SIP (5060/5061):

VoIP call signaling

RTP:

voice and video media transport

Presentation:

Acts as a data translator. Takes data from the application layer, changes the format, encrypts it, or compresses it so that different computer systems can understand each other

Session:

Sets up, manages, and closes communication links between programs on different devices. It acts like a coordinator for a phone call, making sure the connection stays open, flows smoothly, and ends the right way.

Transport:

TCP: reliable, connection-oriented, sequencing, acknowledgments (guaranteed delivery)

UDP: fast, connectionless, low overhead (prioritizes speed)

Network:

It handles logical addressing, packet routing, and forwarding data across different networks. It takes segments from the transport layer, turns them into packets, and finds the best path to the destination.

Internet Control Message Protocol (ICMP):

send error alerts and operational status info (ping and diagnostics) / (tests connectivity)

Open Shortest Path First (OSPF):

routing protocol used by routers to find best path for data inside a single network or autonomous system (routes inside networks)

Border Gateway Protocol (BGP):

core routing protocol of the internet (routes the internet)

Generic Routing Encapsulation (GRE):

a tunneling protocol developed by Cisco that wraps data packets inside another protocol header

Internet Protocol Security (IPsec):

group of protocols that secures communication over public networks like the internet (secure VPN encryption)

Multiprotocol Label Switching (MPLS):

a high performance networking method that directs data packets along predetermined paths using short labels instead of long IP addresses

Virtual Extensible LAN (VXLAN):

a network virtualization technology that extends Layer 2 networks over a Layer 3 infrastructure by wrapping Ethernet frames inside UDP packets

Data Link:

It moves data safely between directly connected nodes on the same local network. This layer takes packets from the network layer, turns them into frames, adds physical MAC addresses, and checks for transmission errors

ARP:

IP to MAC resolution

Ethernet:

local area network (LAN) communication

Spanning Tree Protocol (STP):

prevent switching loops

Link Aggregation Control Protocol (LACP):

link aggregation – ensure high availability

Virtual Local Area Network (VLAN):

network segmentation

Physical:

Transmit raw, unstructured binary data bits across a physical network medium (cables, fiber, radio waves, etc.). Turns digital data into physical light, radio signals, electricity