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Johnson Controls simplifies remote access to legacy, on-prem apps with Azure AD and F5 BIG-IP APM
Published Aug 04 2020 09:00 AM 7,719 Views

For organizations that operate a hybrid environment with a mix of on-premises and cloud apps, shifting to remote work in response to COVID-19 has not been easy. VPN solutions can be clumsy and slow, making it difficult for users to access legacy apps based on-premises or in private clouds. For today’s “Voice of the Customer” post, Nitin Aggarwal, Global Identity Security Engineer at Johnson Controls, describes how his organization overcame these challenges using the rich integration between Azure Active Directory (Azure AD) and F5 BIG-IP Access Policy Manager (F5 BIG-IP APM).


Enabling remote work in a hybrid environment

By Nitin Aggarwal, Global Identity Security Engineer, Johnson Controls


Johnson Controls is the world’s largest supplier of building products, technologies, and services. For more than 130 years, we’ve been making buildings smarter and transforming the environments where people live, work, learn and play. In response to COVID-19, Johnson Controls moved 50,000 non-essential employees to remote work in three weeks. As a result, VPN access increased by over 200 percent and usage spiked to 100 percent throughout the day. People had trouble sharing and were forced to sign in multiple times. To address this challenge, we enabled capabilities in F5 and Azure AD to simplify access to our on-premises apps and implement better security controls. 

Securing a hybrid infrastructure

Our organization relies on a combination of hybrid and software-as-a-solution (SaaS) apps, such as Zscaler and Workday, to conduct business-critical work. Our hybrid application set contains some legacy apps that are built on a code base that can’t be updated. One example is a directory access app that we use to look up employee information like first name, last name, global ID, and phone number. It’s critical that we keep this data protected, yet we also need to make our apps available to employees working offsite.


Johnson Controls uses Azure AD to make over 150 Microsoft and non-Microsoft SaaS apps accessible from anywhere. Many of our legacy apps, however, use header-based authentication, which does not easily integrate with modern authentication standards. To enable single sign-on (SSO) to legacy apps for workers inside the network, we used a Web Access Management (WAM) solution. Remote workers used a VPN. The long-term strategy is to modernize these apps, eliminate them, or migrate them to Azure. In the meantime, we need to make them more accessible.

About five months ago we began an initiative to enable authentication to our legacy apps using Azure AD. We wanted to make access easier and apply security controls, including conditional access. Initially we planned to rewrite the authentication model to support Azure AD, but all these apps use different code. Some were built with .NET. Others were written in Java or Linux. It wasn’t possible to apply a single approach and quickly modernize authentication.  

Migrating legacy apps to Azure AD in less than one hour

When our Microsoft team learned about our issues with our on-premises apps, they suggested we talk to F5. Johnson Controls uses F5 for load balancing, and F5 offers a product, F5 BIG-IP Access Policy Manager (F5 BIG-IP APM), that leverages the load-balancing solution to easily integrate with Azure AD. It requires no timely development work, which was exactly what we were looking for.

If an app is already behind the F5 load balancer and the right team is in place, it can take as little as one hour to migrate apps to Azure AD authentication using F5 BIG-IP APM. We just needed to create the appropriate configurations in F5 and Azure AD. Once the apps are onboarded, whenever a user signs in, they are redirected to Azure AD. Azure AD authenticates the user, sends the attributes back to the legacy app and inserts them in the header. For users, the experience is the same whether they are accessing an on-premises app or a cloud app. They sign in once using SSO and gain access to both cloud and legacy apps. It’s completely seamless.

We started the onboarding process in November. After we moved to remote work in response to the epidemic, we accelerated the schedule. So far, we’ve migrated about 30 apps. We have 15 remaining. 


Implementing a Zero Trust security strategy

With authentication for our apps handled by Azure AD, we can put in place the right security controls. Our security strategy is driven by a Zero Trust model. We don’t automatically trust anything that tries to access the network. As we move workloads to the cloud and enable remote work, it’s important to verify the identity of devices, users and services that try to connect to our resources.

To protect our identities, we’ve enabled a conditional access policy in conjunction with multi-factor authentication (MFA). When users are inside the network on a domain-joined device or connected via VPN, they can access with just a password. Anybody outside the networks must use MFA to gain access. We are also using Azure AD Privileged Identity Management to protect global administrators. With Privileged Identity Manager, users who want to access sensitive resources sign in using a different set of credentials from the ones they use for routine work. This makes it less likely that those credentials will be compromised.

With Azure AD, we also benefit from Microsoft’s scale and availability. Before we migrated our apps from the WAM to Azure AD, there were frequently problems with access related to the WAM. With Azure AD we no longer worry about downtime. Remote work is easier for employees, and we feel more secure.

Support enabling remote work

If your organization relies on legacy apps for business-critical work, I hope you’ve found this blog useful. In the coming months, as you continue to support employees working from home, refer to the following resources for tips on improving the experience for you and your employees.

Top 5 ways you Azure AD can help you enable remote work

Developing applications for secure remote work with Azure AD

Microsoft’s COVID-19 response


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