Integration of On-Premises Network with AWS Cloud.

5 min readJun 6, 2023

In today’s interconnected world, businesses often seek efficient ways to optimize their infrastructure and improve connectivity between on-premises resources and cloud services. One such approach involves utilizing a Microsoft DNS server located in the AWS cloud to facilitate DNS resolution for on-premises hosts. This blog post will explore the setup and benefits of this topology, focusing on a scenario where an on-premises web server is accessed through DNS resolution via a Microsoft DNS server on AWS. Let’s dive in!

Understanding the Topology:

The topology comprises an on-premises host, a Microsoft DNS server hosted on AWS, and a web server residing within the on-premises network. The following are the key network parameters involved:

    On-Premises Host:
        IP Address: 192.168.163.154
        Gateway: 192.168.163.2

    Microsoft DNS Server (AWS Cloud):
        IP Address: 3.84.124.30

    On-Premises Web Server:
        IP Address: 192.168.163.200

Setting Up the Microsoft DNS Server on AWS: To enable DNS resolution for the on-premises host, you need to set up a Microsoft DNS server within an AWS EC2 instance. Here’s a step-by-step process to achieve this:

Launch an EC2 instance in AWS and install the Microsoft DNS server software.
Set up the necessary firewall rules to allow DNS traffic (port 53) between the on-premises network and the AWS cloud.
Ensure that the DNS server has proper connectivity and can communicate with both the on-premises host and the web server.

Checking connectivity between On-Prem and Cloud

Configuring the On-Premises Host: To utilize the Microsoft DNS server for DNS resolution, you need to configure the DNS settings on the on-premises host. Follow these steps:

Access the network settings on the on-premises host and navigate to the DNS configuration.
Set the primary DNS server to the IP address of the Microsoft DNS server hosted in AWS (3.84.124.30).
Optionally, you can add a secondary DNS server for redundancy or fallback purposes.
Save the settings and ensure that the on-premises host can communicate with the DNS server.

To configure a new A host in DNS with a primary zone as “mydns.com” and a host name as “mycisco” with an FQDN as “mycisco.mydns.com,” follow these steps:

Access the DNS management interface:

Log in to the server hosting the DNS server software.
Open the DNS management tool, such as the Microsoft DNS Manager.

Create a new primary zone:

Right-click on the DNS server name in the DNS management tool.
Select “New Zone” from the context menu.
Follow the wizard to create a new primary zone with the domain name “mydns.com.”

Create a new A record for the host:

Navigate to the newly created “mydns.com” zone.
Right-click on the zone and select “New Host (A or AAAA).”
Enter “mycisco” as the host name.
Enter the IP address associated with the “mycisco” host.
Click “Add Host” to create the A record.

Verify the FQDN:

The FQDN for the host “mycisco” should automatically be set as “mycisco.mydns.com” since it is within the “mydns.com” zone.

Save and apply changes:

Save the changes made to the DNS configuration.

Test the DNS resolution:

On a client machine or the on-premises host, open a command prompt or terminal.
Use the “nslookup” command followed by the host name to test DNS resolution. Example: nslookup mycisco.mydns.com
Verify that the DNS resolution returns the correct IP address associated with the “mycisco” host

DNS Resolution Flow: With the setup in place, let’s understand how DNS resolution takes place:

When the on-premises host attempts to connect to the web server using its hostname or fully qualified domain name (FQDN), the DNS resolution process begins.
The on-premises host sends a DNS query to the configured Microsoft DNS server (3.84.124.30) in the AWS cloud.
The Microsoft DNS server receives the query and checks its DNS records for the requested hostname or FQDN.
If a matching record is found, the Microsoft DNS server responds to the on-premises host with the IP address of the web server (192.168.163.200).
The on-premises host then establishes a connection to the web server using the provided IP address.
Subsequent communication between the on-premises host and the web server takes place directly, without involving the Microsoft DNS server.

Web Server access using Domain Name configured on AWS Cloud.

Why launching a DNS server in the cloud, such as AWS, is beneficial, presented in bullet points:

Scalability and Elasticity: Cloud platforms allow you to scale resources based on demand, enabling you to adjust the capacity of the DNS server to handle varying traffic loads effectively.
Redundancy and High Availability: Cloud providers offer redundant infrastructure to minimize downtime in case of failures, ensuring reliable DNS resolution for on-premises hosts.
Global DNS Infrastructure: Cloud platforms have a global network of DNS servers, reducing latency by resolving DNS queries from nearby servers and improving performance for users worldwide.
Security and Compliance: Cloud providers implement robust security measures, protecting your DNS infrastructure and data through encryption, compliance frameworks, and industry best practices.
Simplified Management and Maintenance: Cloud-based DNS servers provide intuitive management interfaces and APIs, making it easier to configure DNS settings, manage DNS records, and monitor DNS traffic.
Cost Optimization: Cloud platforms offer flexible pricing models, allowing you to align expenses with traffic patterns, optimize costs, and benefit from cost optimization tools and features.

In summary, launching a DNS server in the cloud brings scalability, high availability, global reach, enhanced security, simplified management, and cost optimization advantages. These benefits make cloud-based DNS servers an attractive option for businesses seeking to optimize their DNS infrastructure and improve connectivity between on-premises resources and cloud services.

Integration of On-Premises Network with AWS Cloud.

Written by Sadananda.S