http://www.rfc-editor.org/rfc/rfc8203.txt
RFC 8203: BGP Administrative Shutdown Communication, J. Snijders, J. Heitz, J. Scudder2017-07-01T23:00:00-00:00This document enhances the BGP Cease NOTIFICATION message "Administrative Shutdown" and "Administrative Reset" subcodes for operators to transmit a short freeform message to describe why a BGP session was shutdown or reset. This document updates RFC 4486.