Did you ever think about how the application that runs on AWS gets communicated to the database? Or, how can the employees get access to the company applications without connecting to the office network?
Well, the solution is cloud networking.
In the current scenario, companies are shifting their applications, databases, and IT infrastructure to cloud platforms. However, only shifting the resources to the cloud does not help. The resources need to communicate effectively with each other.
This is when cloud networking plays an important role.
So, let us discuss the concept of cloud networking, its working, and its importance.
Cloud Networking Meaning
Cloud networking involves connecting different cloud-based services such as virtual machines, databases, applications, and storage facilities so as to facilitate interaction between these components.
In normal networking, organizations employ physical switches, routers, wires, and firewalls in order to meet their networking needs.
Cloud networking offers equivalent networking features via cloud platforms.
Rather than setting up every networking component physically, cloud networking makes it possible to establish networks using the cloud console, command-line interfaces, and infrastructure-as-code techniques.
For instance, let us consider the case of a firm that has established its website on an EC2 instance of AWS.
The website needs to communicate with the database, which is located on Amazon RDS.
Why Is Cloud Networking So Important?
Consider an office environment in which the employees have access to computers, printers, servers, and other devices. When these devices cannot communicate with one another, all the workflow becomes challenging.
This same concept applies to the cloud environment as well.
An application in the cloud uses several services. Each of these services requires proper networking to work.
reasons for importance of cloud networking.
1. Communication between Cloud Resources
Several servers and databases can be used by applications. Cloud networking helps these resources communicate using network paths.
2. Security
All cloud resources should not be accessible via the internet.
For instance, while there is need for internet connection for a web site that is available on the internet, its database should not be publicly accessible. Network security policies will assist in ensuring that this is done.
3. Scalability
As an organization grows in size, there are needs for more servers, networks and applications.
Cloud networking makes it easy to scale the network without the need for physical network equipment each time.
4. Remote Access
There may be need for remote workers to be able to connect to the organization's network.
Components of Cloud Networking
In order to have an understanding of cloud networking, there are some key concepts that you must learn about.
1. Virtual Private Cloud (VPC)
Virtual Private Cloud, or simply VPC, is a logically isolated network where you can create and manage your cloud resources.
In the case of AWS, you can create a VPC with the network range of `10.0.0.0/16` where you can manage your subnets and routing tables. A VPC can be considered as your personal private network in the cloud environment.
2. Subnets
A subnet is a division of a network into smaller segments within the network.
For instance, take a VPC network that has the network address of “10.0.0.0/16”.
The following are examples of subnets:
Public subnet: 10.0.1.0/24
Private subnet: 10.0.2.0/24
The web server can be hosted on the public subnet while the database server is hosted on the private subnet.
Keep in mind that a subnet does not have to be public or private based on its IP address. The configuration of the route determines how it communicates with other networks.
3. Route tables
A route table tells the destination of network traffic.
Let’s say that a server must send traffic to some other network. The route table will help to figure out the destination of this traffic.
In AWS, the typical route in a public subnet looks like this:
0.0.0.0/0 → Internet Gateway
It will redirect all the traffic bound for other IPv4 networks to the Internet Gateway.
But having an Internet Gateway route is not enough for making an EC2 instance publicly available.
4. Internet Gateway
Internet Gateway enables resources within the VPC to connect to the Internet, given the proper configuration for routing, addressing, and security.
For instance, a web server running a public website will be able to use the Internet Gateway to accept requests from the internet.
5. NAT Gateway
What if you have a server that is hosted in a private subnet and yet must download software updates?
NAT Gateway enables eligible resources in a private subnet to initiate connections to the Internet while blocking any incoming internet connections through that NAT Gateway.
For instance, a private EC2 instance must download some packages via DNF or YUM.
6. Security Groups and Network ACLs
Security is one of the key elements of cloud networking.
Security groups are virtual firewalls in AWS, which are associated with various resources, like EC2 instances and network interfaces; they regulate both incoming and outgoing traffic.
Network Access Control List, or Network ACL, works on the subnet level and allows both allow and deny rules.
For instance, you may configure your web server to allow access to HTTP on port 80 and to HTTPS on port 443.
You may also allow access to databases only from the security group of the application server rather than allow access to everyone.
How Does Cloud Networking Work in Real Life?
To comprehend this, let us take the example of a three-tier application on AWS.
Consider an e-commerce website having three tiers,
1. Web Tier
The web tier gets the request from the user and serves the website.
2. Application Tier
The application tier does all the business logic such as customer login, product search and ordering.
3. Database Tier
The database tier maintains the data such as customers' information, products and orders.
All these tiers communicate through the network, but not all tiers should be publicly accessible.
For example,
➢ The customers can access the publicly accessible website via HTTPS protocol.
➢ The web tier can communicate with the application tier via permitted ports.
➢ The application tier can access the database via the port required by the database.
Public Network vs Private Network in the Cloud
The first concept that a newcomer should get acquainted with in cloud networking is the distinction between public and private subnets.
In its turn, a public subnet is a subnet that has a route to the Internet Gateway.
A private subnet is not connected directly through the route to the Internet Gateway; hence it does not give resources internet connectivity.
Nevertheless, the resources in private subnets may access the external services using NAT Gateway, proxy, and other configurations of the network.
Being a public subnet does not imply that all resources inside of it will be exposed to the internet.
What Is VPC Peering?
Let’s assume that one organization has two VPCs.
In one VPC, there is an application, but in another – shared services. And this company needs to have communication between resources of these networks in a private way.
VPC Peering is able to make a private connection between two VPCs.
Once the peering connection is established, the proper routes and security settings need to be set up.
For instance:
VPC A – 10.0.0.0/16
VPC B – 172.16.0.0/16
What Is a VPN in Cloud Networking?
Virtual Private Network or VPN is the establishment of an encrypted connection through a base network.
For instance, there could be an office network and an AWS VPC. There could be a need for secure access to the cloud-based resources from the employees or systems on the office network.
Site-to-site VPN can be set up between the office network and the cloud network through the use of an encrypted tunnel.
The cloud service providers have their own way of allowing connections to be established remotely to corporate resources.
For instance, Microsoft Azure has Virtual Network (VNet), Azure Load Balancer, Azure VPN Gateway and Azure DNS services.
Google Cloud has Virtual Private Cloud networking, Cloud Load Balancing, Cloud VPN and Cloud DNS services.
Career Opportunities in Cloud Networking
Networking in the cloud is helpful to anyone who likes studying networking, cloud computing, infrastructure, and cybersecurity.
Career options include
➢ Cloud Network Engineer
➢ Cloud Engineer
➢ Network Administrator
➢ Infrastructure Engineer
➢ DevOps Engineer
➢ Cloud Security Engineer
Author:
Chaitanya Kasarla
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Chaitanya Kasarla
Expert trainer and consultant at SevenMentor with years of industry experience. Passionate about sharing knowledge and empowering the next generation of tech leaders.