Connecting the Dots: Understanding Networking Concepts (Part 3/12)

Just as roads and highways connect cities, cloud networking provides the virtual infrastructure for data and applications to flow within and across cloud environments. Let’s explore how cloud networking makes all the magic of the cloud possible.

IP (Internet Protocol) Addresses and Ports

• IP Address: Like a unique address for your house, an IP address identifies devices on a network. It allows devices to communicate with each other.
• IPv4 vs. IPv6: IPv4 (e.g., 192.168.1.1) the most common format, provides a limited number of unique addresses (2³² devices). IPv6 offers a significantly larger address space (2¹²⁸ devices) to accommodate the growth of the internet.
• Ports: Think of ports as doors into a building (your IP address). Each port is assigned a number and is associated with specific types of traffic or application. Some of the classic ports are 22 (SSH for remote access), 21 (FTP for transferring files), 80 (HTTP) and 443 (HTTPS)
• AWS Elastic IP Addresses: Provide static, public IP addresses for your AWS resources. This is useful when you need a consistent IP address even if you stop and start instances, or for masking failures.

DNS: The Internet’s Address Book

• DNS (Domain Name Service) is like the internet’s directory. It translates human-readable domain names (like www.google.com) into the machine-readable IP addresses (like 74.125.24.106) that computers use to communicate.
• When you type in a website address, your browser contacts a DNS resolver, which might be from your ISP or a public service like Cloudflare (1.1.1.1).
• If the resolver doesn’t have the answer, it first queries the Root nameservers, which then provides the address to the TLD nameservers (Top Level Domain e.g. .com), which then provides the address of the Authoritative nameservers (e.g. wikipedia.org) holding the actual DNS records for a domain providing the final IP address.
• A DNS record has several record types like A (Address maps hostname like example.com to IPv4), AAAA (maps hostname to IPv6), CNAME (Canonical Name creates an alias, pointing one hostname to another).
• AWS Route 53: Amazon’s highly available and scalable DNS service. With Route 53 you can register and manage domain names, create and configure various DNS records, use health checks and traffic routing features to keep your applications responsive.

Virtual Networks within the Cloud

• A Virtual Private Cloud (VPC) is like a secure private space in the cloud where you choose its address range. For example, IP addresses in your home network is part of a private network that is not directly accessible publicly. This is made possible through CIDR (Classless Inter-Domain Routing) which is a method of assigning addresses allocated to the private cloud. For example, you can use AWS VPC to create a virtual network.
• Subnets are smaller divisions within your VPC, like rooms. This helps you organize your cloud resources and control how they talk to each other. Each subnet is tied to a specific location (called an Availability Zone) for backup and reliability.
• An Internet Gateway lets you connect your VPC to the internet, so things inside your network can access websites and other online resources. E.g. AWS NAT Gateway lets your cloud computers in private subnets reach the internet. It’s especially useful if you want to keep some things private but still let them get updates or send information out.
• A Route Table is like a map telling your network how to move information around. It decides if traffic goes to the Internet Gateway, to other VPCs you might connect to, or to services within the cloud.

Load Balancers

Imagine a bustling intersection needing a traffic conductor. Load Balancers distribute incoming requests across multiple servers, ensuring efficiency and preventing any one server from being overwhelmed. (AWS Examples: Application Load Balancer, Network Load Balancer)

Content Delivery Networks (CDNs)

CDNs bring your content closer to users. They cache data in geographically distributed locations, resulting in faster website loading times and smoother video streaming, even for users across the globe. (AWS Example: Amazon CloudFront)

Example: Building a Web Application in the Cloud

1. VPC: Create a secure virtual network using AWS VPC, with appropriate subnets.
2. Load Balancer: Use an Application Load Balancer (ALB) to distribute traffic for high availability.
3. CDN: Integrate Amazon CloudFront for faster content delivery to users globally.