Networking devices connect end devices and forward, control, secure, or extend communication.
👉 Unlike end devices, they forward traffic.
A Gateway is a device that connects two different networks using different protocols.
🡪 It acts as a translator between networks.
• Converts data from one protocol to another
• Connects LAN to WAN / Internet
• Acts as an entry and exit point of a network
• Performs routing + protocol conversion
• Often includes firewall and NAT features
• Home Wi-Fi router = Gateway between your home network and ISP
• Email gateway → converts internal mail format to internet format
• Gateway works at multiple OSI layers
• Can combine router + firewall + NAT
A Router connects multiple networks and forwards data using IP addresses.
• Routes packets between networks
• Uses routing table
• Selects best path for data
• Connects LAN to WAN
• Supports static & dynamic routing
• Performs NAT (Network Address Translation)
• Can block or allow traffic using ACLs
• Internet router at home
• Office router connecting branches
• Works at OSI Layer 3 (Network Layer)
• Uses IP addresses
• Slower than switches but smarter
A Switch connects multiple devices within the same network and forwards data using MAC addresses.
• Connects devices in LAN
• Learns MAC addresses automatically
• Sends data only to intended device
• Reduces network congestion
• Supports VLANs
• Supports full-duplex communication
• Stores MAC Address + Port Number
• Office LAN switch
• College computer lab
• Works at OSI Layer 2 (some are Layer 3)
• Faster than hubs
• More secure than hubs
A Hub is a basic device that connects multiple devices and broadcasts data to all ports.
• Connects multiple devices
• Sends data to every device
• No intelligence
• No MAC table
• Works in half-duplex
• High collisions
• No security
• Slow performance
• Works at OSI Layer 1 (Physical)
• Almost obsolete
A Firewall is a security device that monitors and controls incoming and outgoing traffic.
• Allows or blocks traffic
• Protects from unauthorized access
• Filters traffic using rules
• Prevents attacks
• Logs network activity
• Supports VPN
• Hardware firewall
• Software firewall
• Network firewall
• Next-Generation Firewall (NGFW)
• Office security firewall
• Windows Firewall
• Works mainly at Layer 3 & 4
• Security device, not routing device
An Access Point allows wireless devices to connect to a wired network.
• Provides Wi-Fi connectivity
• Converts wired signal to wireless
• Extends network coverage
• Manages wireless clients
• Supports authentication & encryption
• College Wi-Fi AP
• Office ceiling-mounted AP
• Works at Layer 2
• Used in WLAN
A Modem converts digital data to analog and analog to digital.
(MO = Modulator, DEM = Demodulator)
• Connects ISP to customer network
• Signal conversion
• Enables internet connectivity
• Broadband modem
• Fiber ONT
• Used for ISP communication
• Required for internet access
A Bridge connects two LAN segments and filters traffic using MAC address.
• Reduces network traffic
• Divides LAN into segments
• Filters unnecessary traffic
• Improves performance
• Works at Layer 2
• Older technology (replaced by switches)
A Repeater regenerates and amplifies signals to extend network distance.
• Boosts weak signals
• Extends cable length
• Used in long-distance networks
• Wi-Fi repeater at home
• Signal booster
• Works at Layer 1
• No filtering or security
| Device | Layer | Role |
|---|---|---|
| Hub | L1 | Broadcast |
| Repeater | L1 | Signal Boost |
| Bridge | L2 | Segment LAN |
| Switch | L2 | Forward by MAC |
| Router | L3 | Route by IP |
| Firewall | L3/4 | Security |
| AP | L2 | Wireless |
| Modem | Physical | ISP |
| Gateway | Multiple | Protocol Translation |
If asked:
🡪 Difference between Router and Switch
Say:
A switch works within a network using MAC addresses, while a router connects different networks using IP addresses.
Networking accessories are supporting hardware components that help connect, test, organize, and maintain a computer network.
👉 They do not control traffic like routers/switches, but without them, a network cannot work properly.
A NIC is a hardware component that allows a device to connect to a network.
👉 Without NIC, a device cannot communicate on a network.
• Wired NIC (Ethernet)
• Wireless NIC (Wi-Fi)
• Integrated NIC (inbuilt on motherboard)
• External NIC (USB adapter)
• Provides physical connection to network
• Converts data into signals
• Assigns MAC address to device
• Sends and receives data frames
• Works as communication interface between device and network
• Each NIC has a unique MAC address
• Works at OSI Layer 1 & 2
RJ45 is a standard connector used to connect Ethernet cables to networking devices.
RJ = Registered Jack
45 = Connector standard
• Connects LAN cable to devices
• Provides secure physical connection
• Supports Ethernet communication
• Used with UTP/STP cables
• T568A
• T568B (most commonly used)
• LAN cable to PC
• Switch to router connection
• Used in Ethernet networks
• Has 8 pins (8P8C)
A LAN tester is a device used to check LAN cable connectivity and wiring faults.
• Tests cable continuity
• Detects open/short circuit
• Verifies correct pin sequence
• Identifies cross or straight cable
• Saves troubleshooting time
• Ensures proper cable crimping
• Avoids network issues
• Essential for network technicians
• Used during network installation & troubleshooting
• Does not transmit data
A Mount Box is a protective box used to mount networking devices or cable termination points on walls.
• Protects network cables & ports
• Organizes cable termination
• Prevents physical damage
• Improves cable management
• Gives clean professional finish
• Offices
• Colleges
• Data rooms
• Homes
• Physical infrastructure component
• Helps in structured cabling
| Networking Device | Networking Accessory |
|---|---|
| Controls traffic | Supports connection |
| Example: Router | Example: RJ45 |
| Intelligent | Non-intelligent |
If asked:
👉 “What is the role of networking accessories?”
Say confidently:
Networking accessories support the physical and logical connectivity of a network by enabling connection, testing, and management of network components.
• NIC → Connects device to network
• RJ45 → Connects LAN cable to device
• LAN Tester → Tests cable health
• Mount Box → Protects and organizes cables
👉Join our 45-Day Job-Oriented Networking Internship program.
Networking vendors are companies that design, manufacture, and support networking hardware and software used in enterprise, data centers, ISPs, and cloud environments.
Cisco is the world’s largest and most trusted networking company.
Most enterprise networks globally use Cisco devices.
• ISR (Integrated Services Router)
• ASR (Aggregation Services Router)
Functions:
• Routing between networks
• WAN connectivity
• NAT, VPN, ACL support
• Catalyst Series
• Nexus Series (Data Center)
Functions:
• LAN switching
• VLANs, Trunking
• High-speed data transfer
• Cisco Access Points
• Wireless LAN Controllers (WLC)
• Cisco ASA Firewall
• Cisco Firepower (NGFW)
• Enterprises
• ISPs
• Data Centers
• Large offices
• CCNA
• CCNP
• CCIE
👉 Cisco devices are known for stability, scalability, and enterprise-level features.
Juniper is famous for high-performance networking and is widely used by service providers and ISPs.
• MX Series
• PTX Series
Functions:
• High-speed routing
• ISP backbone networks
• EX Series
• QFX Series (Data Center)
• SRX Firewalls
• Uses Junos OS (single OS across devices)
• ISPs
• Telecom companies
• Large enterprises
• JNCIA
• JNCIS
• JNCIE
About Palo Alto
Palo Alto is a pure security-focused company, famous for Next-Generation Firewalls.
• PA-Series Hardware Firewalls
• VM-Series (Virtual Firewall)
• Application-based filtering
• Threat prevention
• Intrusion prevention
• URL filtering
• VPN support
• Identifies traffic by application, not just port
• Enterprises
• Banks
• Government networks
👉 Palo Alto firewalls are application-aware firewalls.
About Ubiquiti
Ubiquiti is popular for cost-effective networking solutions, mainly for SMBs (Small & Medium Businesses).
• UniFi Switch
• UniFi Access Point
• UniFi Gateway
• Wi-Fi connectivity
• LAN switching
• Centralized cloud management
• Easy web-based management
• Affordable pricing
• Small offices
• Colleges
• Homes
• Startups
👉 Ubiquiti is known for budget-friendly enterprise-grade networking.
About Arista
Arista specializes in high-speed data center networking and cloud environments.
• Arista 7000 Series
• Arista 7500 Series
• Ultra-low latency switching
• Cloud-scale networking
• High-speed data transfer (10G, 40G, 100G)
• Uses EOS (Extensible Operating System)
• Highly programmable
• Data centers
• Cloud providers
• Large-scale enterprises
👉 Arista is widely used in cloud and hyperscale data centers.
| Vendor | Famous For | Used In |
| Cisco | Routers, Switches | Enterprise |
| Juniper | High-speed routing | ISP |
| Palo Alto | Firewalls | Security |
| Ubiquiti | Affordable networking | SMB |
| Arista | Data center switches | Cloud |
C-J-P-U-A
👉 Cisco – Enterprise
👉 Juniper – ISP
👉 Palo Alto – Security
👉 Ubiquiti – SMB
👉 Arista – Data Center
If interviewer asks:
👉 “Which vendor is best for what?”
Answer confidently:
Cisco for enterprise networking, Juniper for service providers, Palo Alto for security firewalls, Ubiquiti for cost-effective SMB networks, and Arista for high-performance data centers.
🚀 Want to learn more about networking and real-world technologies?
https://www.evisiontechnoserve.com/internships/it/45-days-job-internship-program-live
