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Showing posts with the label RADIUS

Microsoft NPS as a RADIUS Server for WiFi Networks: Dynamic VLAN Assignment

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The Microsoft Network Policy Server (NPS) is often used as a RADIUS server for WiFi networks. It can provide authentication and authorization services for users on a wireless network.
In this article we take a look at how users can be dynamically assigned to a VLAN that suits their account privileges, using RADIUS attributes passed back from NPS to the RADIUS client (usually a wireless LAN controller or access point).
This method of assigning a user to a particular VLAN based on their login credentials is also known as Role Based Access Control (RBAC). 

As wireless networks have grown to provide more and more services to organisations, the practice of creating a new SSID for each new service required has fallen out of favour, as each SSID adds more overhead to the RF medium, reducing the available bandwidth for all wireless services. 
Best practice in terms of the number of SSIDs you should have available from your wireless network is generally accepted to be around 4 or 5 SSIDs as a maxi…

Microsoft NPS as a RADIUS Server for WiFi Networks: Self Signed Certificate

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The Microsoft Network Policy Server (NPS) is often used as a RADIUS server for WiFi networks. It can provide authentication and authorization services for users on a wireless network.
Generally, NPS is used with various EAP methods (e.g. PEAP, EAP-TLS) that require a certificate to be presented by the NPS server to the client as part of the authentication exchange. The certificate proves the identity of NPS (the RADIUS authentication server)  to the client and is used to derive keys to build a TLS tunnel for the secure exchange of credential information.
Most of the time, a Microsoft PKI infrastructure is used to issue a certificate to the NPS server, which is a relatively straightfoward process that is well documented in official Microsoft documentation.
However, there may be times when you want to fire up a version of NPS (perhaps in a lab or POC environment) and just put on your own self-signed certificate, instead of having the additional overhead of getting CA servers etc. going.
Fin…

Microsoft NPS as a RADIUS Server for WiFi Networks: RADIUS Client Limits

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The Microsoft Network Policy Server (NPS) is often used as a RADIUS server for WiFi networks. It can provide authentication and authorization services for users on a wireless network.

I put this document together to highlight one particular little 'gotcha' when using NPS with Windows 2008.
Windows 2008 comes in three flavours: Data CentreEnterpriseStandard When using NPS as a RADIUS server, you have to add a number of 'RADIUS clients' to the configuration of the NPS server. These are the devices on your WiFi network that will send the RADIUS requests to NPS each time a user tries to logon to the network. The screenshot below shows where RADIUS clients are configured in NPS:

The RADIUS request contains username and password information for the user trying to logon to the network. The request is generally checked against a Windows AD domain to see if the user is supplying a valid set of AD credentials to access the WiFi network.
In controller-based WiFi networks (e.g. Cis…