rfc9915v5.txt   rfc9915.txt 
skipping to change at line 12 skipping to change at line 12
Internet Engineering Task Force (IETF) T. Mrugalski Internet Engineering Task Force (IETF) T. Mrugalski
Request for Comments: 9915 ISC Request for Comments: 9915 ISC
STD: 102 B. Volz STD: 102 B. Volz
Obsoletes: 8415 Individual Contributor Obsoletes: 8415 Individual Contributor
Category: Standards Track M. Richardson Category: Standards Track M. Richardson
ISSN: 2070-1721 SSW ISSN: 2070-1721 SSW
S. Jiang S. Jiang
BUPT BUPT
T. Winters T. Winters
QA Cafe QA Cafe
December 2025 January 2026
Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
Abstract Abstract
This document specifies the Dynamic Host Configuration Protocol for This document specifies the Dynamic Host Configuration Protocol for
IPv6 (DHCPv6), an extensible mechanism for configuring nodes with IPv6 (DHCPv6), an extensible mechanism for configuring nodes with
network configuration parameters, IP addresses, and prefixes. network configuration parameters, IP addresses, and prefixes.
Parameters can be provided statelessly or in combination with Parameters can be provided statelessly or in combination with
stateful assignment of one or more IPv6 addresses and/or IPv6 stateful assignment of one or more IPv6 addresses and/or IPv6
skipping to change at line 47 skipping to change at line 47
received public review and has been approved for publication by the received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841. Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata, Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9915. https://www.rfc-editor.org/info/rfc9915.
Copyright Notice Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Revised BSD License text as described in Section 4.e of the include Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described Trust Legal Provisions and are provided without warranty as described
skipping to change at line 663 skipping to change at line 663
5.2. Client/Server Exchanges Involving Four Messages 5.2. Client/Server Exchanges Involving Four Messages
To request the assignment of one or more addresses and/or delegated To request the assignment of one or more addresses and/or delegated
prefixes, a client first locates a DHCP server and then requests the prefixes, a client first locates a DHCP server and then requests the
assignment of addresses and/or delegated prefixes and other assignment of addresses and/or delegated prefixes and other
configuration information from the server. The client sends a configuration information from the server. The client sends a
Solicit message to the All_DHCP_Relay_Agents_and_Servers multicast Solicit message to the All_DHCP_Relay_Agents_and_Servers multicast
address to find available DHCP servers. Any server that can meet the address to find available DHCP servers. Any server that can meet the
client's requirements responds with an Advertise message. The client client's requirements responds with an Advertise message. The client
then chooses one of the servers and sends a Request message to the then chooses one of the servers and sends a Request message to the
server asking for confirmed assignment of addresses and/or delegated server asking for the lease of addresses and/or delegated prefixes
prefixes and other configuration information. The server responds and other configuration information. The server responds with a
with a Reply message that contains the confirmed addresses, delegated Reply message that contains the leased addresses, delegated prefixes,
prefixes, and configuration. and configuration.
As described in the previous section, the client can request an As described in the previous section, the client can request an
extension of the lifetimes assigned to addresses or delegated extension of the lifetimes assigned to addresses or delegated
prefixes (this is a two-message exchange). prefixes (this is a two-message exchange).
5.3. Server/Client Exchanges 5.3. Server/Client Exchanges
A server that has previously communicated with a client and A server that has previously communicated with a client and
negotiated for the client to listen for Reconfigure messages may send negotiated for the client to listen for Reconfigure messages may send
the client a Reconfigure message to initiate the client to update its the client a Reconfigure message to initiate the client to update its
skipping to change at line 5668 skipping to change at line 5668
* In enterprise and factory networks, use of authentication per * In enterprise and factory networks, use of authentication per
[IEEE8802.1x] can prevent unknown or untrusted clients from [IEEE8802.1x] can prevent unknown or untrusted clients from
connecting to the network. However, this does not necessarily connecting to the network. However, this does not necessarily
assure that the connected client will be a good DHCP or network assure that the connected client will be a good DHCP or network
actor. actor.
* For wired networks where clients typically are connected to a * For wired networks where clients typically are connected to a
switch port, snooping DHCP multicast (or unicast) traffic becomes switch port, snooping DHCP multicast (or unicast) traffic becomes
difficult, as the switches limit the traffic delivered to a port. difficult, as the switches limit the traffic delivered to a port.
The client's DHCP multicast messages (with destination address The client's DHCP messages (multicast to
ff02::1:2) are only forwarded to the DHCP server's (or relay's) All_DHCP_Relay_Agents_and_Servers) are only forwarded to the DHCP
switch port -- not all ports. Also, the server's (or relay's) server's (or relay's) switch port -- not all ports. Also, the
unicast replies are only delivered to the target client's port -- server's (or relay's) unicast replies are only delivered to the
not all ports. target client's port -- not all ports.
* In public networks (such as a Wi-Fi network in a coffee shop or * In public networks (such as a Wi-Fi network in a coffee shop or
airport), it is possible for others within radio range to snoop airport), it is possible for others within radio range to snoop
DHCP and other traffic. But in these environments, there is very DHCP and other traffic. But in these environments, there is very
little if anything that can be learned from the DHCP traffic little if anything that can be learned from the DHCP traffic
itself (either from client to server or from server to client) if itself (either from client to server or from server to client) if
the privacy considerations provided in Section 23 are followed. the privacy considerations provided in Section 23 are followed.
Even for devices that do not follow the privacy considerations, Even for devices that do not follow the privacy considerations,
there is little that can be learned that would not be available there is little that can be learned that would not be available
from subsequent communications anyway (such as the device's Media from subsequent communications anyway (such as the device's Media
 End of changes. 4 change blocks. 
11 lines changed or deleted 11 lines changed or added

This html diff was produced by rfcdiff 1.48.