SuperMicro IPMI using Windows-based RADIUS (NPS)

I'm struggling to use a Windows-based RADIUS setup (Network Policy Server) with SuperMicro IPMI interfaces.

I've found that I need to add vendor-specific attribute H=4, I=4 (Appendix C in the SuperMicro IPMI manual), but I'm not sure about some of the settings needed to configure the NPS policy:

I think I'm missing the either the Vendor Code or the vendor-assigned attribute number, which both should be a numerical value. The attribute value itself is the H=4, I=4 string.

I found this article looking for advice on how to configure this in NPS. I was able to figure this out, no thanks to SuperMicro support:

Service-Type: Login
Vendor Specific Attribute > Add
Vendor Code: 10876
Yes. It Conforms >
Vendor-assigned attribute number: 1
Attribute format: string
Attribute value: H=4, I=4

the answer from Justin Redenbach helped me to resolve this issue. We use FortiAuthenticator as the RADIUS Server. I've created a new dictionary for the IPMI and imported it as a file:

VENDOR  IPMI    10876
BEGIN-VENDOR    IPMI
ATTRIBUTE   Permissions 1   string  BOTH
END-VENDOR  IPMI

Then I configured the user to have the attribute values H=4, I=4.

user config in FortiAuthenticator

With this configuration it worked like a charm

Theoretically it should also be possible to add the attribute values directly into the dictionary but for some reason it didn't work. The dictionary should look something like that:

VENDOR  IPMI    10876
BEGIN-VENDOR    IPMI
ATTRIBUTE   Permissions 1   string  BOTH
VALUE   UserPermissions H=4, I=4    1
END-VENDOR  IPMI

I didn't investigate further this problem as adding the values directly to the user worked for me