Why Are Firewalls So Important to a Cloud Migration?

What is the essence of a cloud migration? What major function does cloud migration provide?
Simply stated, the general purpose of a cloud migration is to move resources in the datacenter to a cloud provider (such as Microsoft Azure cloud). These resources can include, but are not limited to:

• general-purpose servers
• routers
• switches
• circuits
• databases/data warehouses
• applications
• file shares/file servers
• client computers (using technologies such as Azure VDI or Windows 365)
• email and productivity software access (using technologies such as M365 [formerly Office 365])

And so much more.

Recently, I discussed two primary reasons companies are moving to the cloud. Please view my previous post on why companies migrate to Azure if you would like that information about the process.
Now, let’s look at the total migration objectively.

We are taking both data and data processing structures from our SECURE data centers that have gained our trust over the last years (even decades, at some Enterprises), and we are moving them to a new location. Even if this location was a vault in the FBI, there would be an element of concern about the overall effectiveness of the new location’s security process.

This security concern is one of the most important challenges to overcome with any Azure cloud migration. Specifically, the client or company’s concern that even with a super-secure company like Microsoft, the design of the new environment — or more specifically, the process used to migrate and position the resources — will not be as secure as what is already in the current ‘legacy’ datacenter.
This is where the firewall comes into play.

The firewall is key and very important to the migration process to help reduce concerns like this, both logically and practically. In short, firewalls are resources that function as guards at the gate; they either allow data to pass along or reject it.

Typically, a Network Engineer will program a process/algorithm that will instruct the firewall what data to accept. The standard practice in Network Engineering is to list everything that will be accepted. The last step is to essentially ‘deny anything that does not fit what I have already allowed.’ In Network Engineering lingo, this is called the ‘deny all’ statement.

The usual configurations for a firewall include a name or label for each rule, the source IP address, the destination IP address, the ports that should be allowed, and the protocols that should be allowed. I have added an example below this statement:

Name: NEW_RDP_PORTS_CR19521958
Protocol: TCP
Source Addresses:
Destination IP Adresses:
Destination Ports: 81052

Do you notice the part of the name that’s written as “CR19521958” in the above example? It is added to define the Change Management request that approved placing this new rule into the infrastructure.

Now that we have all of that out of the way, let’s quickly answer the question at hand:

Why are firewalls so important to a cloud migration?

The simple answer is that they are a key line of defense against data hacks — infrastructure security.

Basically, a firewall (or many of them) is the first device that all data is filtered through as soon as it is out of the WAN cloud (think internet traffic; coming and going). This super-specific filtering process adds major security to any environment — and that makes your Cyber Security team VERY HAPPY!


Why Do Companies Migrate to Azure?

In modern business, one of the areas expanding exponentially is Microsoft Azure’s cloud computing. More and more institutions, as well as individuals, are moving their computer-related tasks to Azure. This is part of the cloud computing age, which is going to grow more and more in the coming years.

Now, this raises a question: Why do companies migrate to Microsoft Azure?

There are many answers to this question. However, I will focus on two major reasons why companies migrate to Microsoft Azure: Reducing costs and increasing performance.


If I could pick one driver for migrating to Azure, it would be reducing costs. Remember, the cloud (including Azure, AWS, GCP, and more) is just a set of large datacenters that you rent to host your Information Technology tools. You pay a recurring cost to have the luxury of using another datacenter to run your tools.

With Azure cloud usage, you can reduce the overall Information Technology costs for some of the following reasons:

  1. No need to purchase and warranty servers
  2. No need to purchase and warranty routers and switches
  3. No need to purchase and warranty network area storage devices
  4. No need to purchase and warranty storage area network devices
  5. A cost reduction as you do not need to purchase and insure a building for a datacenter
  6. A cost reduction as you do not need to purchase and maintain the network connectivity for the building
  7. A cost reduction as you do not need to pay for the electricity to the building


These costs are given to Microsoft (if you are using Azure cloud), and the overall costs are then divided into hourly/computer-usage units, so you are only charged for what you use. Most businesses only use a small fraction of the total computer power available to them, so the costs are a fraction of what the current spending is.


One of the largest advantages that Microsoft Azure presents is its ability to increase performance. Microsoft is continually building more servers across the United States and the world at large.
As these new datacenters are constructed, the latest and greatest physical devices and networking are used to provide users with the best experience in Azure. Additionally, new tools are continuously being made available in the various portals for Azure, which increase the options for performance and optimizing execution.

With Azure cloud usage, you can increase the overall performance of your Information Technology infrastructure for some of the following reasons:

  1. You can increase application compute resources within seconds
  2. You can increase application network resources within seconds
  3. You can increase application storage resources within seconds
  4. You can increase application database resources within seconds
  5. You can increase application security resources within seconds
  6. You can link multiple copies of an application infrastructure (redundancy) for near 100% availability
  7. The supporting platform in Microsoft Azure will have the latest updates, improving performance and stability


For so many reasons like the ones above, it is easy to see why companies are eager to move more tools to the cloud — YOU ARE GETTING MORE PERFORMANCE FOR LESS COST.