Network Components

Basics of Network Components

Router

• Function: Routes data packets between different networks.
• Use Cases: Connecting multiple networks, directing internet traffic, establishing VPNs.
• Security Benefits: Network segmentation, access control, VPN support.

Switch

• Function: Connects devices within a single network based on MAC addresses.
• Use Cases: Local network connectivity, VLAN segmentation, improving network performance.
• Security Benefits: VLAN support, port security, network monitoring.

Proxy Server

• Function: Acts as an intermediary between clients and servers, handling requests on behalf of clients.
• Use Cases: Content caching, web filtering, anonymizing internet access.
• Security Benefits: IP address hiding, content filtering, malware scanning.

Wireless Access Point (WAP)

• Function: Provides wireless network access to devices.
• Use Cases: Wireless connectivity, BYOD environments, extending network coverage.
• Security Benefits: Encryption (WPA3), access control (SSID broadcast control, MAC filtering).

Reverse Proxy

• Function: Acts as an intermediary for requests from clients seeking resources from servers. It forwards client requests to the appropriate server and returns the server’s response to the client.
• Use Cases: Enhancing security by hiding the server’s IP address, providing load balancing, caching content, and facilitating secure communication (e.g., SSL termination).
• Security Benefits: Protects backend servers from direct exposure to the internet, helps mitigate DDoS attacks, and can enforce web application firewall (WAF) policies.

API Gateway

• Function: Manages, secures, and routes API calls between clients and backend services. It can also handle tasks such as request validation, rate limiting, authentication, and authorization.
• Use Cases: Centralizing API management, simplifying client access to multiple services, applying consistent security policies, and transforming API requests and responses.
• Security Benefits: Enforces security policies like authentication and authorization, protects against API abuse (e.g., rate limiting), and provides monitoring and logging of API activities.

Load Balancer

• Function: Distributes incoming network or application traffic across multiple servers to ensure no single server becomes overwhelmed, thereby improving the availability and reliability of applications.
• Use Cases: Enhancing the performance and availability of web applications, balancing traffic loads, and providing redundancy.
• Security Benefits: Can act as a point of enforcement for SSL/TLS encryption, helps mitigate certain types of DDoS attacks by distributing traffic, and improves overall system resilience.

Firewall

• Function: Monitors and controls incoming and outgoing network traffic based on predetermined security rules.
• Use Cases: Protecting network perimeters, segmenting internal networks, controlling access to resources, and preventing unauthorized access.
• Security Benefits: Blocks malicious traffic, enforces access control policies, and prevents unauthorized access to network resources.

VPN Gateway

• Function: Establishes secure connections between an on-premises network and an Azure virtual network over a public network using VPN protocols.
• Use Cases: Securely connecting remote offices or users to the corporate network, extending on-premises networks to the cloud.
• Security Benefits: Encrypts data in transit, protects data from interception, and ensures secure access to network resources.

Web Application Firewall (WAF)

• Function: Protects web applications by filtering and monitoring HTTP requests and blocking malicious traffic.
• Use Cases: Protecting web applications from common web exploits like SQL injection, cross-site scripting (XSS), and other OWASP Top 10 vulnerabilities.
• Security Benefits: Shields applications from common web threats, provides logging and alerting for security events, and enforces security policies to protect web applications.

DNS Firewall

• Function: Filters DNS queries to block access to known malicious domains and prevent data exfiltration through DNS.
• Use Cases: Blocking access to malicious sites, preventing DNS-based attacks, and enforcing acceptable use policies.
• Security Benefits: Protects against phishing and malware domains, prevents data exfiltration through DNS tunneling, and enhances overall network security.

Intrusion Detection System (IDS) / Intrusion Prevention System (IPS)

• Function: Monitors network traffic for suspicious activity and potential threats; IDS alerts on detected threats while IPS can take action to block or mitigate them.
• Use Cases: Detecting and preventing network-based attacks, monitoring network traffic for anomalies, and enhancing threat detection capabilities.
• Security Benefits: Identifies and blocks malicious traffic, provides real-time threat detection, and enhances the overall security posture by preventing attacks.

Network Address Translation (NAT) Gateway

• Function: Translates private IP addresses to public IP addresses (and vice versa) to enable communication between internal and external networks.
• Use Cases: Enabling internet access for resources with private IP addresses, conserving public IP addresses, and securing internal network architecture.
• Security Benefits: Hides internal IP addresses from external entities, reduces the attack surface by using fewer public IP addresses, and controls outbound traffic.