Dell EMC Configuration Guide for the S4048T–ON System 9.14.2.4

CoA Packet Processing

This section lists various actions that the NAS performs during CoA packet processing.

The following activities are performed by NAS:

• responds with CoA-Nak, if no matching session is found for the session identification attributes in CoA; Error-Cause value is “Session Context Not Found” (503).
• responds with CoA-Nak, for any internal processing error in NAS; Error-Cause value is “Resources Unavailable” (506).
• ignores attributes that are supported as per RFC but irrelevant to the CoA operations.
• responds to a CoA-Request containing one or more incorrect attribute values with a CoA-Nak; Error-Cause value is “Invalid Attribute Value” (407).
  NOTE

  The Invalid Attribute Value Error-Cause is applicable to following scenarios:

  • if the CoA request contains incorrect Vendor-Specific attribute value.
  • if the CoA request contains incorrect NAS-port or calling-station-id values.
• rejects the CoA-Request containing NAS-IP-Address or NAS-IPV6-Address attribute that does not match the NAS with a CoA-Nak; Error-Cause value is “NAS Identification Mismatch” (403).
• responds with a CoA-Nak, if it is configured to prohibit honoring of corresponding CoA-Request messages; Error-Cause value is “Administratively Prohibited” (501).
  NOTE

  The Administratively Prohibited Error-Cause is also applicable to following scenarios:

  • if the dot1x feature is not enabled in the NAS-port.
  • if the NAS-port state is administratively down.