draft-ietf-dhc-mac-assign-01.txt   draft-ietf-dhc-mac-assign-02.txt 
Dynamic Host Configuration (DHC) B. Volz Dynamic Host Configuration (DHC) B. Volz
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Standards Track T. Mrugalski Intended status: Standards Track T. Mrugalski
Expires: March 23, 2020 ISC Expires: July 10, 2020 ISC
CJ. Bernardos CJ. Bernardos
UC3M UC3M
September 20, 2019 January 7, 2020
Link-Layer Addresses Assignment Mechanism for DHCPv6 Link-Layer Addresses Assignment Mechanism for DHCPv6
draft-ietf-dhc-mac-assign-01 draft-ietf-dhc-mac-assign-02
Abstract Abstract
In certain environments, e.g. large scale virtualization deployments, In certain environments, e.g. large scale virtualization deployments,
new devices are created in an automated manner. Such devices new devices are created in an automated manner. Such devices
typically have their link-layer (MAC) addresses randomized. With typically have their link-layer (MAC) addresses randomized. With
sufficient scale, the likelihood of collision is not acceptable. sufficient scale, the likelihood of collision is not acceptable.
Therefore an allocation mechanism is required. This draft proposes Therefore an allocation mechanism is required. This draft proposes
an extension to DHCPv6 that allows a scalable approach to link-layer an extension to DHCPv6 that allows a scalable approach to link-layer
address assignments. address assignments.
skipping to change at page 1, line 39 skipping to change at page 1, line 39
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 23, 2020. This Internet-Draft will expire on July 10, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2020 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 Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
skipping to change at page 8, line 14 skipping to change at page 8, line 14
The DHCPv6 mechanisms are reused to large degree, including message The DHCPv6 mechanisms are reused to large degree, including message
and option formats, transmission mechanisms, relay infrastructure and and option formats, transmission mechanisms, relay infrastructure and
others. However, a device wishing to support only link-layer address others. However, a device wishing to support only link-layer address
assignment is not required to support full DHCPv6. In other words, assignment is not required to support full DHCPv6. In other words,
the device may support only assignment of link-layer addresses, but the device may support only assignment of link-layer addresses, but
not IPv6 addresses or prefixes. not IPv6 addresses or prefixes.
6. Information Encoding 6. Information Encoding
A client MUST send a LLADDR option encapsulated in a IA_LL option to A client MUST send a LLADDR option encapsulated in an IA_LL option to
specify the link-layer-type and link-layer-len values. For link- specify the link-layer-type and link-layer-len values. For link-
layer-type 1 (Ethernet / IEEE 802 48-bit MAC addresses), a client layer-type 1 (Ethernet / IEEE 802 48-bit MAC addresses), a client
sets the link-layer-address field to: sets the link-layer-address field to:
1. 00:00:00:00:00:00 (all zeroes) if the client has no hint as to 1. 00:00:00:00:00:00 (all zeroes) if the client has no hint as to
the starting address of the unicast address block. This address the starting address of the unicast address block. This address
has the IEEE 802 individual/group bit set to 0 (individual). has the IEEE 802 individual/group bit set to 0 (individual).
3. Any other value to request a specific block of address starting 2. Any other value to request a specific block of address starting
with the specified address with the specified address
A client sets the extra-addresses field to either 0 for a single A client sets the extra-addresses field to either 0 for a single
address or to the size of the requested address block minus 1. address or to the size of the requested address block minus 1.
A client SHOULD set the valid-lifetime field to 0 (as it is ignored A client SHOULD set the valid-lifetime field to 0 (this field MUST be
by the server). ignored by the server).
7. Requesting Addresses 7. Requesting Addresses
The link-layer addresses are assigned in blocks. The smallest block The link-layer addresses are assigned in blocks. The smallest block
is a single address. To request an assignment, the client sends a is a single address. To request an assignment, the client sends a
Solicit message with a IA_LL option in the message. The IA_LL option Solicit message with an IA_LL option in the message. The IA_LL
MUST contain a LLADDR option as specified in Section 6. option MUST contain a LLADDR option as specified in Section 6.
The server, upon receiving a IA_LL option, inspects its content and The server, upon receiving an IA_LL option, inspects its content and
may offer an address or addresses for each LLADDR option according to may offer an address or addresses for each LLADDR option according to
its policy. The server MAY take into consideration the address block its policy. The server MAY take into consideration the address block
requested by the client in the LLADDR option. However, the server requested by the client in the LLADDR option. However, the server
MAY chose to ignore some or all parameters of the requested address MAY chose to ignore some or all parameters of the requested address
block. In particular, the server may send a different starting block. In particular, the server may send a different starting
address than requested, or grant a smaller number of addresses than address than requested, or grant a smaller number of addresses than
requested. The server sends back an Advertise message an IA_LL requested. The server sends back an Advertise message an IA_LL
option containing an LLADDR option that specifies the addresses being option containing an LLADDR option that specifies the addresses being
offered. If the server is unable to provide any addresses it MUST offered. If the server is unable to provide any addresses it MUST
return the IA_LL option containing a Status Code option (see return the IA_LL option containing a Status Code option (see
skipping to change at page 9, line 15 skipping to change at page 9, line 15
The client MUST be able to handle a response that contains an address The client MUST be able to handle a response that contains an address
or addresses different than those requested. or addresses different than those requested.
The client waits for available servers to send Advertise responses The client waits for available servers to send Advertise responses
and picks one server as defined in Section 18.2.9 of [RFC8415]. The and picks one server as defined in Section 18.2.9 of [RFC8415]. The
client then sends a Request message that includes the IA_LL container client then sends a Request message that includes the IA_LL container
option with the LLADDR option copied from the Advertise message sent option with the LLADDR option copied from the Advertise message sent
by the chosen server. by the chosen server.
Upon reception of a Request message with IA_LL container option, the Upon reception of a Request message with IA_LL container option, the
server assigns requested addresses. The server MAY alter the server assigns requested addresses. The server allocates block of
allocation at this time. It then generates and sends a Reply message addresses according to its configured policy. The server MAY assign
back to the client. a different block than requested in the Request message. It then
generates and sends a Reply message back to the client.
Upon receiving a Reply message, the client parses the IA_LL container Upon receiving a Reply message, the client parses the IA_LL container
option and may start using all provided addresses. It MUST restart option and may start using all provided addresses. It MUST restart
its T1 and T2 timers using the values specified in the IA_LL option. its T1 and T2 timers using the values specified in the IA_LL option.
The client MUST be able to handle a Reply message that contains an The client MUST be able to handle a Reply message that contains an
address or addresses different than those requested. address or addresses different than those requested.
A client that has included a Rapid Commit option in the Solicit, may A client that has included a Rapid Commit option in the Solicit, may
receive a Reply in response to the Solicit and skip the Advertise and receive a Reply in response to the Solicit and skip the Advertise and
skipping to change at page 11, line 9 skipping to change at page 11, line 9
Figure 2: IA_LL Option Format Figure 2: IA_LL Option Format
option-code OPTION_IA_LL (tbd1). option-code OPTION_IA_LL (tbd1).
option-len 12 + length of IA_LL-options field. option-len 12 + length of IA_LL-options field.
IAID The unique identifier for this IA_LL; the IAID must IAID The unique identifier for this IA_LL; the IAID must
be unique among the identifiers for all of this be unique among the identifiers for all of this
client's IA_LLs. The number space for IA_LL IAIDs is client's IA_LLs. The number space for IA_LL IAIDs is
separate from the number space for other IA option separate from the number space for other IA option
types (i.e., IA_NA, IA_TA, and IA_PD). A four octets types (i.e., IA_NA, IA_TA, and IA_PD). A 4-octet
long field. field containing an unsigned integer.
T1 The time at which the client should contact the T1 The time at which the client should contact the
server from which the addresses in the IA_LL were server from which the addresses in the IA_LL were
obtained to extend the valid lifetime of the obtained to extend the valid lifetime of the
addresses assigned to the IA_LL; T1 is a time addresses assigned to the IA_LL; T1 is a time
duration relative to the current time expressed in duration relative to the current time expressed in
units of seconds. A four octets long field. units of seconds. A 4-octet field containing an
unsigned integer.
T2 The time at which the client should contact any T2 The time at which the client should contact any
available server to extend the valid lifetime of the available server to extend the valid lifetime of the
addresses assigned to the IA_LL; T2 is a time addresses assigned to the IA_LL; T2 is a time
duration relative to the current time expressed in duration relative to the current time expressed in
units of seconds. A four octets long field. units of seconds. A 4-octet field containing an
unsigned integer.
IA_LL-options Options associated with this IA_LL. A variable IA_LL-options Options associated with this IA_LL. A variable
length field (12 octets less than the value in the length field (12 octets less than the value in the
option-len field). option-len field).
An IA_LL option may only appear in the options area of a DHCP An IA_LL option may only appear in the options area of a DHCP
message. A DHCP message may contain multiple IA_LL options (though message. A DHCP message may contain multiple IA_LL options (though
each must have a unique IAID). each must have a unique IAID).
The status of any operations involving this IA_LL is indicated in a The status of any operations involving this IA_LL is indicated in a
skipping to change at page 13, line 12 skipping to change at page 13, line 12
The format of the Link-Layer Addresses option is: The format of the Link-Layer Addresses option is:
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_LLADDR | option-len | | OPTION_LLADDR | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| link-layer-type | link-layer-len | | link-layer-type | link-layer-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | . .
| link-layer-address | . link-layer-address .
| | . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| extra-addresses | | extra-addresses |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| valid-lifetime | | valid-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. . . .
. LLaddr-options . . LLaddr-options .
. . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 13, line 40 skipping to change at page 13, line 40
LLaddr-options field. Assuming a typical link-layer LLaddr-options field. Assuming a typical link-layer
address of 6 is used and there are no extra options, address of 6 is used and there are no extra options,
length should be equal to 18. length should be equal to 18.
link-layer-type The link-layer type MUST be a valid hardware type link-layer-type The link-layer type MUST be a valid hardware type
assigned by the IANA, as described in [RFC5494]. The assigned by the IANA, as described in [RFC5494]. The
type is stored in network byte order. type is stored in network byte order.
link-layer-len Specifies the length of the link-layer-address field link-layer-len Specifies the length of the link-layer-address field
(typically 6, for a link-layer-type of 1 (Ethernet)). (typically 6, for a link-layer-type of 1 (Ethernet)).
A two octets long field. A 2-octet field containing an unsigned integer.
link-layer-address Specifies the link-layer address that is being link-layer-address Specifies the link-layer address that is being
requested or a special value to request any address. requested or renewed, or a special value to request
For a link-layer type of 1 (Ethernet / IEEE 802 any address. For a link-layer type of 1 (Ethernet /
48-bit MAC addresses), see Section 6 for details on IEEE 802 48-bit MAC addresses), see Section 6 for
these values. This value can be only sent by a details on these values. In responses from a server,
client that requests a new block. In responses from this value specifies the first address allocated.
a server, this value specifies the first address
allocated.
extra-addresses Number of additional addresses that follow the extra-addresses Number of additional addresses that follow the
address specified in link-layer-address. For address specified in link-layer-address. For a
requesting a single address, use 0. For example: single address, 0 is used. For example: link-layer-
link-layer-address: 02:04:06:08:0a and extra- address: 02:04:06:08:0a and extra-addresses 3
addresses 3 designates a block of 4 addresses, designates a block of 4 addresses, starting from
starting from 02:04:06:08:0a (inclusive) and ending 02:04:06:08:0a (inclusive) and ending with
with 02:04:06:08:0d (inclusive). In responses from a 02:04:06:08:0d (inclusive). In responses from a
server, this value specifies the number of additional server, this value specifies the number of additional
addresses allocated. A four octets long field. addresses allocated. A 4-octet field containing an
unsigned integer.
valid-lifetime The valid lifetime for the address(es) in the option, valid-lifetime The valid lifetime for the address(es) in the option,
expressed in units of seconds. A four octets long expressed in units of seconds. A 4-octet field
field. containing an unsigned integer.
LLaddr-options Any encapsulated options that are specific to this LLaddr-options Any encapsulated options that are specific to this
particular address block. Currently there are no particular address block. Currently there are no
such options defined, but there may be in the future. such options defined, but there may be in the future.
In a message sent by a client to a server, the valid lifetime field In a message sent by a client to a server, the valid lifetime field
SHOULD be set to 0. The server MUST ignore any received value. SHOULD be set to 0. The server MUST ignore any received value.
In a message sent by a server to a client, the client MUST use the In a message sent by a server to a client, the client MUST use the
value in the valid lifetime field for the valid lifetime for the value in the valid lifetime field for the valid lifetime for the
 End of changes. 20 change blocks. 
39 lines changed or deleted 41 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/