target = "https://www.rfc-editor.org/rfc/rfc9000#section-9.6.2"

# 9.6.2.  Migration to a Preferred Address
#
# A client that migrates to a preferred address MUST validate the
# address it chooses before migrating; see Section 21.5.3.
# 
# A server might receive a packet addressed to its preferred IP address
# at any time after it accepts a connection.  If this packet contains a
# PATH_CHALLENGE frame, the server sends a packet containing a
# PATH_RESPONSE frame as per Section 8.2.  The server MUST send non-
# probing packets from its original address until it receives a non-
# probing packet from the client at its preferred address and until the
# server has validated the new path.
# 
# The server MUST probe on the path toward the client from its
# preferred address.  This helps to guard against spurious migration
# initiated by an attacker.
# 
# Once the server has completed its path validation and has received a
# non-probing packet with a new largest packet number on its preferred
# address, the server begins sending non-probing packets to the client
# exclusively from its preferred IP address.  The server SHOULD drop
# newer packets for this connection that are received on the old IP
# address.  The server MAY continue to process delayed packets that are
# received on the old IP address.
# 
# The addresses that a server provides in the preferred_address
# transport parameter are only valid for the connection in which they
# are provided.  A client MUST NOT use these for other connections,
# including connections that are resumed from the current connection.

[[spec]]
level = "MUST"
quote = '''
A client that migrates to a preferred address MUST validate the
address it chooses before migrating; see Section 21.5.3.
'''

[[spec]]
level = "MUST"
quote = '''
The server MUST send non-
probing packets from its original address until it receives a non-
probing packet from the client at its preferred address and until the
server has validated the new path.
'''

[[spec]]
level = "MUST"
quote = '''
The server MUST probe on the path toward the client from its
preferred address.
'''

[[spec]]
level = "SHOULD"
quote = '''
The server SHOULD drop
newer packets for this connection that are received on the old IP
address.
'''

[[spec]]
level = "MAY"
quote = '''
The server MAY continue to process delayed packets that are
received on the old IP address.
'''

[[spec]]
level = "MUST"
quote = '''
A client MUST NOT use these for other connections,
including connections that are resumed from the current connection.
'''