Azure Multi-Factor Authentication
Multi-Factor Authentication (MFA) is a method of authentication that requires the use of more than one verification method and adds a critical second layer of security to user sign-ins and transactions. It works by requiring any two or more of the following verification methods:
Something you know (typically a password)
Something you have (a trusted device that is not easily duplicated, like a phone)
Something you are (biometrics)
Azure MFA is a method of verifying who you are that requires the use of more than just a username and password. It provides a second layer of security to user sign-ins and transactions.
Azure MFA helps safeguard access to data and applications while meeting user demand for a simple sign-in process. It delivers strong authentication with a range of easy verification options - phone call, text message or mobile app notification - allowing users to choose the method they prefer.
Azure MFA is an easy to use, scalable and reliable solution that provides a second method of authentication so your users are always protected.
The security of multi-factor authentication lies in its layered approach. Comprising multiple authentication factors presents a significant challenge for attackers. Even if an attacker manages to learn the user's password, it is useless without also having possession of the trusted device. Should the user lose the device, the person who finds it will not be able to use it unless they also know the user's password.
This document provides step-by-step instructions on how to configure Azure, the MFA server and the Kemp LoadMaster in order to provide multi-factor authentication.
This document uses an Exchange environment as an example scenario.
This document is intended to be used by anyone interested in finding out more about using Azure MFA with the Kemp LoadMaster.
The Network Policy Server (NPS) extension for Azure Multi-Factor Authentication (MFA) adds cloud-based MFA capabilities to your authentication infrastructure using your existing servers. For more information, refer to the Integrate your existing NPS infrastructure with Azure Multi-Factor Authentication page.
You must create a RADIUS client so that the LoadMaster can authenticate. For more information, refer to the RADIUS Authentication and Authorization Technical Note.
Follow the steps in the sub-sections below to configure the LoadMaster.
The L7 Authentication Timeout should be increased in order to provide enough time for the following actions to occur:
The user enters their credentials
Azure MFA communicates with the service in the cloud
The service in the cloud sends the authentication to the user's phone (by app or phone call)
To increase the L7 Authentication Timeout, follow the steps below:
1. In the main menu of the LoadMaster WUI, go to System Configuration > Miscellaneous Options > L7 Configuration.
2. Enter the L7 Authentication Timeout and click Set Timeout.
Kemp recommends 300 seconds but this can be adjusted as needed to meet requirements.
You can also adjust the SSO LDAP server timeout by following the steps below:
1. In the main menu of the LoadMaster WUI, go to Virtual Services > Manage SSO > Modify.
2. Configure the Public Session Timeout and click Set Idle Time.
Follow the steps below to create a new SSO domain:
1. In the main menu of the LoadMaster WUI, go to Virtual Services > Manage SSO.
2. Enter a name in the Add new Client Side Configuration text box and click Add.
3. Select RADIUS as the Authentication Protocol.
4. Enter the IP address of the MFA Server in the RADIUS server(s) text box and click Set RADIUS Server(s). Multiple addresses can be entered in this text box, if required.
5. Enter the RADIUS Shared Secret, which was created in the MFA configuration earlier, and click Set Shared Secret.
6. Enter the Domain/Realm and click Set Domain/Realm Name.
Our example is based on using an Exchange environment. For this example scenario, the Edge Security Pack (ESP) Options for the OWA and Authentication Proxy SubVSs need to be configured. To do this, follow the steps below:
1. In the main menu of the LoadMaster WUI, go to Virtual Services > View/Modify Services.
2. Click Modify on the relevant Virtual Service.
3. Expand the ESP Options section.
4. Select Form Based as the Client Authentication Mode.
5. Select the SSO Domain that was created in the previous section.
6. Configure any of the other settings as needed.
You may want to configure a custom SSO Image Set to inform users that MFA will be required. For further information on doing this, please refer to the Custom Authentication Form, Technical Note.
7. Repeat the steps above to configure the other SubVS.
For further information on configuring the LoadMaster to work with Exchange, refer to the relevant Exchange Deployment Guide. For further information on ESP, refer to the ESP, Feature Description.
This document was last updated on 11 March 2022.