RFC 5176, "Dynamic Authorization Extensions to Remote Authentication Dial In User Service (RADIUS)", January 2008Source of RFC: radext (ops)
Errata ID: 2012
Reported By: Avi Lior
Date Reported: 2010-01-25
Verifier Name: Dan Romascanu
Date Verified: 2010-11-02
Section 3.5 says:
Values 200-299 represent successful completion, so that these values may only be sent within CoA-ACK or Disconnect-ACK packets and MUST NOT be sent within a CoA-NAK or Disconnect-NAK packet.
It should say:
Values 200-299 represent successful completion, so that these values may be sent in other reply messages such as Access-Reject, Access-Challenge, CoA-ACK or Disconnect-ACK packets and MUST NOT be sent within a CoA-NAK or Disconnect-NAK packet.
RFC 3579 allows for Error-Cause to be sent (specifically) in an access-challenge and also in Reject messages as well.
The specification in 5176 restricts the usage and should be clarified especially since 5176 was published after 3579.
I proposed minimal text but I think a broader approach is needed for this attribute. Here are some thoughts:
1) Error-Cause is needed in Access-Reject (as is allowed by 3579)
2) IANA should have procedures for defining new values (currently no procedure is defined). SDO need to be able to use Error-Cause to report back why an Authentication/Authorization failed. Error-Cause seems to be the only solution other than Reply-Message which is not really designed for reporting error cause to the NAS.