RADIUS attribute from rfc7268
The EAPoL-Announcement Attribute contains EAPoL-Announcement Type- Length-Value (TLV) tuples defined within Table 11-8 of IEEE-802.1X . The acronym "EAPoL" stands for Extensible Authentication Protocol over Local Area Network. Zero or more EAPoL-Announcement Attributes are permitted within an Access-Request, Access-Accept, Access-Challenge, Access-Reject, Accounting-Request, CoA-Request, or Disconnect-Request packet.When included within an Access-Request packet, EAPoL-Announcement Attributes contain EAPoL-Announcement TLVs that the user sent in an EAPoL-Announcement. When included within an Access-Accept, Access-Challenge, Access-Reject, CoA-Request or Disconnect-Request packet, EAPoL-Announcement Attributes contain EAPoL-Announcement TLVs that the NAS is to send to the user in a unicast EAPoL- Announcement. When sent within an Accounting-Request packet, EAPoL-Announcement Attributes contain EAPoL-Announcement TLVs that the NAS has most recently sent to the user in a unicast EAPoL- Announcement. A summary of the EAPoL-Announcement Attribute format is shown below. The fields are transmitted from left to right. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | String... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 180 Length >=3 String The String field is one or more octets, containing EAPoL- Announcement TLVs in the format defined in Figure 11-8 ofof . Any EAPoL-Announcement TLV Type MAY be included within an EAPoL-Announcement Attribute, including Organizationally Specific TLVs. If multiple EAPoL-Announcement Attributes are present in a packet, their String fields MUST be concatenated before being parsed for EAPoL-Announcement TLVs; this allows EAPoL-Announcement TLVs longer than 253 octets to be transported by RADIUS. Similarly, EAPoL-Announcement TLVs larger than 253 octets MUST be fragmented between multiple EAPoL- Announcement Attributes.