@互联宽带网 Hi,
Thank you for posting in Q&A!
Please understand that since On January 14, 2020, support for Windows Server 2008 and 2008 R2 ended. So we don't have the server 2008R2 environment to test. But I've done research about the corresponding issue, following are my suggestions, hope it will be helpful to you:
According to another user's RADIUS log with NPS server configured MikroTik-specific attributes, it seems that 'MT-wireless-VLAN-ID' is a normal phenomenon.
According to another instruction of how to setup mikrotik vendor specific attributes in nps, the "Attribute Value" for 'Mikrotik_Wireless_VlanID" is 11, which is different from your configuration. For more details, you can refer to:
https://mum.mikrotik.com/presentations/EU18/presentation_5159_1523293520.pdf
Hope you have a nice day!
Gloria
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