Complete thing to know about Routers & Practical Example

 

1. What is a Router?

A router is a networking device that forwards data packets between computer networks. It determines the best path for data to travel from the source to the destination across interconnected networks.

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2. Functions of a Router

1. Routing: Directs data packets between devices across different networks using routing tables and algorithms.
2. Network Segmentation: Divides networks to manage traffic and improve security.
3. NAT (Network Address Translation): Maps private IP addresses to a public IP address for internet access.
4. Firewall Functionality: Provides basic security by filtering traffic and protecting against unauthorized access.
5. Wireless Connectivity: Acts as a Wi-Fi access point in wireless routers.
6. QoS (Quality of Service): Prioritizes certain types of traffic (e.g., VoIP, gaming).

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3. Types of Routers

1. Core Router: High-performance router used in enterprise backbones.
2. Edge Router: Connects an internal network to external networks like the internet.
3. Wireless Router: Combines routing functions with a wireless access point.
4. Virtual Router: Software-based routing using virtual machines.
5. SOHO Router: Designed for small office/home office environments.
6. ISP Router: High-capacity routers used by ISPs to manage internet traffic.

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4. Components of a Router

1. CPU (Processor): Executes routing algorithms and protocols.
2. RAM: Temporary memory for running processes and storing dynamic routing tables.
3. ROM: Contains the router's bootup firmware and diagnostics.
4. Flash Memory: Stores the router's operating system (e.g., Cisco IOS).
5. Ports: Ethernet/WAN/LAN ports for connecting devices and networks.
6. Routing Table: A data table storing the best routes to network destinations.

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5. Routing Protocols

1. Static Routing: Manually configured routes.
2. Dynamic Routing Protocols:
   • RIP (Routing Information Protocol): Distance-vector protocol, limited to small networks.
   • OSPF (Open Shortest Path First): Link-state protocol, suitable for large networks.
   • EIGRP (Enhanced Interior Gateway Routing Protocol): Cisco-proprietary protocol, combines distance-vector and link-state features.
   • BGP (Border Gateway Protocol): Used for routing between ISPs and large networks.

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6. Router Modes

1. User EXEC Mode: Limited access for basic commands.
2. Privileged EXEC Mode: Full access to configuration commands.
3. Global Configuration Mode: Configures router settings.

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7. Key Features

1. Dual-band/tri-band: Operates on 2.4GHz and 5GHz (or more) frequencies.
2. MU-MIMO: Allows multiple devices to communicate simultaneously.
3. Guest Network: Isolates guest traffic from the main network.
4. VPN Support: Allows secure remote connections.
5. Parental Controls: Manages access to websites and internet usage.

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8. Router Security

1. Change Default Credentials: Prevent unauthorized access.
2. Enable Encryption: Use WPA3 or WPA2 for Wi-Fi security.
3. Firewall Settings: Configure the built-in firewall.
4. Firmware Updates: Regular updates to patch vulnerabilities.
5. Disable WPS: WPS can be a security risk.

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9. Troubleshooting Routers

1. Slow Internet: Check for interference, bandwidth hogs, or outdated firmware.
2. Connection Drops: Update firmware, reposition the router, or reset it.
3. No Internet Access: Verify ISP connection, restart the router, and check cables.

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10. Advanced Router Features

1. Mesh Networking: Extends coverage using multiple nodes.
2. Dynamic DNS: Maps a domain name to a dynamic IP address.
3. Port Forwarding: Allows external devices to connect to internal network services.
4. VLAN Support: Segregates network traffic for better performance and security.
5. Load Balancing: Distributes traffic across multiple connections.

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11. Router Brands

1. Consumer Routers: TP-Link, Netgear, ASUS, Linksys.
2. Enterprise Routers: Cisco, Juniper Networks, MikroTik.
3. ISP-grade Routers: Huawei, Nokia, Arris.

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12. Buying Considerations

1. Speed: Look for the latest Wi-Fi standards (e.g., Wi-Fi 6/6E).
2. Range: Determine coverage based on your home or office size.
3. Ports: Ensure sufficient LAN/WAN and USB ports.
4. Processor/RAM: High specs for gaming or heavy usage.
5. Budget: Match features with your budget.

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13. Hands-On Configuration

1. Access Admin Interface: Log in via router's IP address.
2. Basic Setup: Configure SSID, password, and encryption.
3. Advanced Settings: Setup VLANs, port forwarding, and QoS.

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Scenario: Setting up a Wi-Fi Router for Home Use

You just purchased a new router and want to:

1. Configure basic settings.
2. Secure your Wi-Fi network.
3. Optimize it for performance.

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Step-by-Step Configuration

Step 1: Physical Setup

1. Connect the Router:

   • Plug the router into a power source.
   • Use an Ethernet cable to connect your modem (from your ISP) to the router's WAN/Internet port.
   • Connect your laptop/PC to one of the LAN ports on the router using another Ethernet cable.

2. Turn on the Router:

   • Wait for the indicator lights to stabilize (usually takes 1–2 minutes).

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Step 2: Access the Admin Interface

1. Find the Router’s IP Address:

   • Default IPs are often 192.168.0.1 or 192.168.1.1.
   • Check the label on the router or its manual.

2. Log In:

   • Open a browser and type the IP address into the address bar.
   • Enter the default username and password (often admin/admin or admin/password).
   • Change the default credentials immediately for security.

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Step 3: Configure Basic Settings

1. Set the SSID (Wi-Fi Name):

   • Navigate to the Wireless Settings section.
   • Change the default SSID to something recognizable (e.g., “MyHomeWiFi”).

2. Set a Strong Password:

   • Enable WPA3 or WPA2-PSK encryption.
   • Choose a strong password (e.g., a mix of uppercase, lowercase, numbers, and symbols).

3. Select a Wi-Fi Band:

   • If you have a dual-band router:
     • Use 2.4GHz for better range.
     • Use 5GHz for faster speeds and less interference.

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Step 4: Optimize for Performance

1. Channel Selection:

   • Use a Wi-Fi analyzer tool (like NetSpot) to find the least congested channel.
   • Manually set your router to use that channel.

2. Enable QoS (Quality of Service):

   • Prioritize bandwidth for activities like gaming, streaming, or video conferencing.

3. Guest Network:

   • Enable a separate guest network to isolate visitors from your primary network.

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Step 5: Secure the Router

1. Update Firmware:

   • Check the router's admin page for firmware updates and apply them.
   • This patches vulnerabilities and improves performance.

2. Disable WPS:

   • WPS is convenient but often insecure. Turn it off unless absolutely necessary.

3. Enable the Firewall:

   • Use the built-in firewall to block suspicious traffic.

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Step 6: Test and Verify

1. Check Connectivity:

   • Connect a device (phone, laptop) to the new Wi-Fi network.
   • Verify internet access.

2. Speed Test:

   • Use tools like Speedtest.net to measure your network's upload/download speeds.

3. Test Security:

   • Use tools like nmap or online vulnerability scanners (e.g., ShieldsUP!) to check for open ports or insecure settings.

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Advanced Customizations (Optional)

1. Port Forwarding:

   • For gaming or hosting services, forward specific ports to a device.
   • Example: Forward port 80 to host a web server on your local machine.

2. Dynamic DNS (DDNS):

   • Set up a DDNS service to access your network remotely with a custom domain (e.g., "myhome.ddns.net").

3. VLAN Setup:

   • Segregate traffic for IoT devices and ensure they don't have access to sensitive systems.

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Outcome

After following these steps, you will have:

1. A secure Wi-Fi network.
2. Optimized performance for your devices.
3. A configured router ready for advanced use cases.