draft-ietf-dnsext-dhcid-rr-13.txt   rfc4701.txt 
DNSEXT M. Stapp Network Working Group M. Stapp
Internet-Draft Cisco Systems, Inc. Request for Comments: 4701 Cisco Systems, Inc.
Expires: September 23, 2006 T. Lemon Category: Standards Track T. Lemon
Nominum, Inc. Nominum, Inc.
A. Gustafsson A. Gustafsson
Araneus Information Systems Oy Araneus Information Systems Oy
March 22, 2006 October 2006
A DNS RR for Encoding DHCP Information (DHCID RR)
<draft-ietf-dnsext-dhcid-rr-13.txt>
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
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material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at A DNS Resource Record (RR) for Encoding
http://www.ietf.org/ietf/1id-abstracts.txt. Dynamic Host Configuration Protocol (DHCP) Information (DHCID RR)
The list of Internet-Draft Shadow Directories can be accessed at Status of This Memo
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on September 23, 2006. This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The Internet Society (2006).
Abstract Abstract
It is possible for DHCP clients to attempt to update the same DNS It is possible for Dynamic Host Configuration Protocol (DHCP) clients
FQDN or attempt to update a DNS FQDN that has been added to the DNS to attempt to update the same DNS Fully Qualified Domain Name (FQDN)
for another purpose as they obtain DHCP leases. Whether the DHCP or to update a DNS FQDN that has been added to the DNS for another
server or the clients themselves perform the DNS updates, conflicts purpose as they obtain DHCP leases. Whether the DHCP server or the
can arise. To resolve such conflicts, [1] proposes storing client clients themselves perform the DNS updates, conflicts can arise. To
identifiers in the DNS to unambiguously associate domain names with resolve such conflicts, RFC 4703 proposes storing client identifiers
the DHCP clients to which they refer. This memo defines a distinct in the DNS to unambiguously associate domain names with the DHCP
RR type for this purpose for use by DHCP clients and servers, the clients to which they refer. This memo defines a distinct Resource
"DHCID" RR. Record (RR) type for this purpose for use by DHCP clients and
servers: the "DHCID" RR.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology .....................................................3
3. The DHCID RR . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. The DHCID RR ....................................................3
3.1. DHCID RDATA format . . . . . . . . . . . . . . . . . . . . 3 3.1. DHCID RDATA Format .........................................3
3.2. DHCID Presentation Format . . . . . . . . . . . . . . . . 4 3.2. DHCID Presentation Format ..................................4
3.3. The DHCID RR Identifier Type Codes . . . . . . . . . . . . 4 3.3. The DHCID RR Identifier Type Codes .........................4
3.4. The DHCID RR Digest Type Code . . . . . . . . . . . . . . 5 3.4. The DHCID RR Digest Type Code ..............................4
3.5. Computation of the RDATA . . . . . . . . . . . . . . . . . 5 3.5. Computation of the RDATA ...................................5
3.5.1. Using the Client's DUID . . . . . . . . . . . . . . . 5 3.5.1. Using the Client's DUID .............................5
3.5.2. Using the Client Identifier Option . . . . . . . . . . 6 3.5.2. Using the Client Identifier Option ..................6
3.5.3. Using the Client's htype and chaddr . . . . . . . . . 6 3.5.3. Using the Client's htype and chaddr .................6
3.6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.6. Examples ...................................................6
3.6.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 6 3.6.1. Example 1 ...........................................6
3.6.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . 7 3.6.2. Example 2 ...........................................7
3.6.3. Example 3 . . . . . . . . . . . . . . . . . . . . . . 7 3.6.3. Example 3 ...........................................7
4. Use of the DHCID RR . . . . . . . . . . . . . . . . . . . . . 8 4. Use of the DHCID RR .............................................8
5. Updater Behavior . . . . . . . . . . . . . . . . . . . . . . . 8 5. Updater Behavior ................................................8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations .........................................8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations .............................................9
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 8. Acknowledgements ................................................9
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. References ......................................................9
9.1. Normative References . . . . . . . . . . . . . . . . . . . 9 9.1. Normative References .......................................9
9.2. Informative References . . . . . . . . . . . . . . . . . . 10 9.2. Informative References ....................................10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . . . 12
1. Introduction 1. Introduction
A set of procedures to allow DHCP [7] [11] clients and servers to A set of procedures to allow DHCP [7] [11] clients and servers to
automatically update the DNS ([3], [4]) is proposed in [1]. automatically update the DNS ([3], [4]) is proposed in [1].
Conflicts can arise if multiple DHCP clients wish to use the same DNS Conflicts can arise if multiple DHCP clients wish to use the same DNS
name or a DHCP client attempts to use a name added for another name or a DHCP client attempts to use a name added for another
purpose. To resolve such conflicts, [1] proposes storing client purpose. To resolve such conflicts, [1] proposes storing client
identifiers in the DNS to unambiguously associate domain names with identifiers in the DNS to unambiguously associate domain names with
the DHCP clients using them. In the interest of clarity, it is the DHCP clients using them. In the interest of clarity, it is
preferable for this DHCP information to use a distinct RR type. This preferable for this DHCP information to use a distinct RR type. This
memo defines a distinct RR for this purpose for use by DHCP clients memo defines a distinct RR for this purpose for use by DHCP clients
or servers, the "DHCID" RR. or servers: the "DHCID" RR.
In order to obscure potentially sensitive client identifying In order to obscure potentially sensitive client identifying
information, the data stored is the result of a one-way SHA-256 hash information, the data stored is the result of a one-way SHA-256 hash
computation. The hash includes information from the DHCP client's computation. The hash includes information from the DHCP client's
message as well as the domain name itself, so that the data stored in message as well as the domain name itself, so that the data stored in
the DHCID RR will be dependent on both the client identification used the DHCID RR will be dependent on both the client identification used
in the DHCP protocol interaction and the domain name. This means in the DHCP protocol interaction and the domain name. This means
that the DHCID RDATA will vary if a single client is associated over that the DHCID RDATA will vary if a single client is associated over
time with more than one name. This makes it difficult to 'track' a time with more than one name. This makes it difficult to 'track' a
client as it is associated with various domain names. client as it is associated with various domain names.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [2]. document are to be interpreted as described in [2].
3. The DHCID RR 3. The DHCID RR
The DHCID RR is defined with mnemonic DHCID and type code [TBD]. The The DHCID RR is defined with mnemonic DHCID and type code 49. The
DHCID RR is only defined in the IN class. DHCID RRs cause no DHCID RR is only defined in the IN class. DHCID RRs cause no
additional section processing. additional section processing.
3.1. DHCID RDATA format 3.1. DHCID RDATA Format
The RDATA section of a DHCID RR in transmission contains RDLENGTH The RDATA section of a DHCID RR in transmission contains RDLENGTH
octets of binary data. The format of this data and its octets of binary data. The format of this data and its
interpretation by DHCP servers and clients are described below. interpretation by DHCP servers and clients are described below.
DNS software should consider the RDATA section to be opaque. DHCP DNS software should consider the RDATA section to be opaque. DHCP
clients or servers use the DHCID RR to associate a DHCP client's clients or servers use the DHCID RR to associate a DHCP client's
identity with a DNS name, so that multiple DHCP clients and servers identity with a DNS name, so that multiple DHCP clients and servers
may deterministically perform dynamic DNS updates to the same zone. may deterministically perform dynamic DNS updates to the same zone.
From the updater's perspective, the DHCID resource record RDATA From the updater's perspective, the DHCID resource record RDATA
consists of a 2-octet identifier type, in network byte order, consists of a 2-octet identifier type, in network byte order,
followed by a 1-octet digest type, followed by one or more octets followed by a 1-octet digest type, followed by one or more octets
representing the actual identifier: representing the actual identifier:
< 2 octets > Identifier type code < 2 octets > Identifier type code
< 1 octet > Digest type code < 1 octet > Digest type code
< n octets > Digest (length depends on digest type) < n octets > Digest (length depends on digest type)
3.2. DHCID Presentation Format 3.2. DHCID Presentation Format
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followed by a 1-octet digest type, followed by one or more octets followed by a 1-octet digest type, followed by one or more octets
representing the actual identifier: representing the actual identifier:
< 2 octets > Identifier type code < 2 octets > Identifier type code
< 1 octet > Digest type code < 1 octet > Digest type code
< n octets > Digest (length depends on digest type) < n octets > Digest (length depends on digest type)
3.2. DHCID Presentation Format 3.2. DHCID Presentation Format
In DNS master files, the RDATA is represented as a single block in In DNS master files, the RDATA is represented as a single block in
base 64 encoding identical to that used for representing binary data base-64 encoding identical to that used for representing binary data
in [8], Section 3. The data may be divided up into any number of in [8], Section 3. The data may be divided up into any number of
white space separated substrings, down to single base 64 digits, white-space-separated substrings, down to single base-64 digits,
which are concatenated to form the complete RDATA. These substrings which are concatenated to form the complete RDATA. These substrings
can span lines using the standard parentheses. can span lines using the standard parentheses.
3.3. The DHCID RR Identifier Type Codes 3.3. The DHCID RR Identifier Type Codes
The DHCID RR Identifier Type Code specifies what data from the DHCP The DHCID RR Identifier Type Code specifies what data from the DHCP
client's request was used as input into the hash function. The client's request was used as input into the hash function. The
identifier type codes are defined in a registry maintained by IANA, identifier type codes are defined in a registry maintained by IANA,
as specified in Section 7. The initial list of assigned values for as specified in Section 7. The initial list of assigned values for
the identifier type code and that type's identifier is: the identifier type code and that type's identifier is:
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| | of 'chaddr' from a DHCPv4 client's DHCPREQUEST | | | of 'chaddr' from a DHCPv4 client's DHCPREQUEST |
| | [7]. | | | [7]. |
| 0x0001 | The data octets (i.e., the Type and | | 0x0001 | The data octets (i.e., the Type and |
| | Client-Identifier fields) from a DHCPv4 | | | Client-Identifier fields) from a DHCPv4 |
| | client's Client Identifier option [10]. | | | client's Client Identifier option [10]. |
| 0x0002 | The client's DUID (i.e., the data octets of a | | 0x0002 | The client's DUID (i.e., the data octets of a |
| | DHCPv6 client's Client Identifier option [11] | | | DHCPv6 client's Client Identifier option [11] |
| | or the DUID field from a DHCPv4 client's | | | or the DUID field from a DHCPv4 client's |
| | Client Identifier option [6]). | | | Client Identifier option [6]). |
| 0x0003 - 0xfffe | Undefined; available to be assigned by IANA. | | 0x0003 - 0xfffe | Undefined; available to be assigned by IANA. |
| 0xffff | Undefined; RESERVED | | 0xffff | Undefined; RESERVED. |
+------------------+------------------------------------------------+ +------------------+------------------------------------------------+
3.4. The DHCID RR Digest Type Code 3.4. The DHCID RR Digest Type Code
The DHCID RR Digest Type Code is an identifier for the digest The DHCID RR Digest Type Code is an identifier for the digest
algorithm used. The digest is calculated over an identifier and the algorithm used. The digest is calculated over an identifier and the
canonical FQDN as described in the next section. canonical FQDN as described in the next section.
The digest type codes are defined in a registry maintained by IANA, The digest type codes are defined in a registry maintained by IANA,
as specified in Section 7. The initial list of assigned values for as specified in Section 7. The initial list of assigned values for
the digest type codes is: value 0 is reserved and value 1 is SHA-256. the digest type codes is: value 0 is reserved, and value 1 is
Reserving other types requires IETF standards action. Defining new SHA-256. Reserving other types requires IETF standards action.
values will also require IETF standards action to document how DNS Defining new values will also require IETF standards action to
updaters are to deal with multiple digest types. document how DNS updaters are to deal with multiple digest types.
3.5. Computation of the RDATA 3.5. Computation of the RDATA
The DHCID RDATA is formed by concatenating the 2-octet identifier The DHCID RDATA is formed by concatenating the 2-octet identifier
type code with variable-length data. type code with variable-length data.
The RDATA for all type codes other than 0xffff, which is reserved for The RDATA for all type codes other than 0xffff, which is reserved for
future expansion, is formed by concatenating the 2-octet identifier future expansion, is formed by concatenating the 2-octet identifier
type code, the 1-octet digest type code, and the digest value (32 type code, the 1-octet digest type code, and the digest value (32
octets for SHA-256). octets for SHA-256).
< identifier-type > < digest-type > < digest > < identifier-type > < digest-type > < digest >
The input to the digest hash function is defined to be: The input to the digest hash function is defined to be:
digest = SHA-256(< identifier > < FQDN >) digest = SHA-256(< identifier > < FQDN >)
The FQDN is represented in the buffer in the canonical wire format as The FQDN is represented in the buffer in the canonical wire format as
described in [9], section 6.2. The identifier type code and the described in [9], Section 6.2. The identifier type code and the
identifier are related as specified in Section 3.3: the identifier identifier are related as specified in Section 3.3: the identifier
type code describes the source of the identifier. type code describes the source of the identifier.
A DHCPv4 updater uses the 0x0002 type code if a Client Identifier A DHCPv4 updater uses the 0x0002 type code if a Client Identifier
option is present in the DHCPv4 messages and it is encoded as option is present in the DHCPv4 messages and it is encoded as
specified in [6]. Otherwise, the updater uses 0x0001 if a Client specified in [6]. Otherwise, the updater uses 0x0001 if a Client
Identifier option is present and 0x0000 if not. Identifier option is present, and 0x0000 if not.
A DHCPv6 updater always uses the 0x0002 type code. A DHCPv6 updater always uses the 0x0002 type code.
3.5.1. Using the Client's DUID 3.5.1. Using the Client's DUID
When the updater is using the Client's DUID (either from a DHCPv6 When the updater is using the Client's DUID (either from a DHCPv6
Client Identifier option or from a portion of the DHCPv4 Client Client Identifier option or from a portion of the DHCPv4 Client
Identifier option encoded as specified in [6]), the first two octets Identifier option encoded as specified in [6]), the first two octets
of the DHCID RR MUST be 0x0002, in network byte order. The third of the DHCID RR MUST be 0x0002, in network byte order. The third
octet is the digest type code (1 for SHA-256). The rest of the DHCID octet is the digest type code (1 for SHA-256). The rest of the DHCID
skipping to change at page 6, line 39 skipping to change at page 6, line 37
same order in which the octets appear in the DHCPREQUEST message. same order in which the octets appear in the DHCPREQUEST message.
The number of significant octets in the 'chaddr' field is specified The number of significant octets in the 'chaddr' field is specified
in the 'hlen' field of the DHCPREQUEST message. The FQDN data, as in the 'hlen' field of the DHCPREQUEST message. The FQDN data, as
specified above, follows. specified above, follows.
3.6. Examples 3.6. Examples
3.6.1. Example 1 3.6.1. Example 1
A DHCP server allocates the IPv6 address 2001:DB8::1234:5678 to a A DHCP server allocates the IPv6 address 2001:DB8::1234:5678 to a
client which included the DHCPv6 client-identifier option data 00:01: client that included the DHCPv6 client-identifier option data 00:01:
00:06:41:2d:f1:66:01:02:03:04:05:06 in its DHCPv6 request. The 00:06:41:2d:f1:66:01:02:03:04:05:06 in its DHCPv6 request. The
server updates the name "chi6.example.com" on the client's behalf, server updates the name "chi6.example.com" on the client's behalf and
and uses the DHCP client identifier option data as input in forming a uses the DHCP client identifier option data as input in forming a
DHCID RR. The DHCID RDATA is formed by setting the two type octets DHCID RR. The DHCID RDATA is formed by setting the two type octets
to the value 0x0002, the 1-octet digest type to 1 for SHA-256, and to the value 0x0002, the 1-octet digest type to 1 for SHA-256, and
performing a SHA-256 hash computation across a buffer containing the performing a SHA-256 hash computation across a buffer containing the
14 octets from the client-id option and the FQDN (represented as 14 octets from the client-id option and the FQDN (represented as
specified in Section 3.5). specified in Section 3.5).
chi6.example.com. AAAA 2001:DB8::1234:5678 chi6.example.com. AAAA 2001:DB8::1234:5678
chi6.example.com. DHCID ( AAIBY2/AuCccgoJbsaxcQc9TUapptP69l chi6.example.com. DHCID ( AAIBY2/AuCccgoJbsaxcQc9TUapptP69l
OjxfNuVAA2kjEA= ) OjxfNuVAA2kjEA= )
If the DHCID RR type is not supported, the RDATA would be encoded If the DHCID RR type is not supported, the RDATA would be encoded
[13] as: [13] as:
\# 35 ( 000201636fc0b8271c82825bb1ac5c41cf5351aa69b4febd94e8f17cd \# 35 ( 000201636fc0b8271c82825bb1ac5c41cf5351aa69b4febd94e8f17cd
b95000da48c40 ) b95000da48c40 )
3.6.2. Example 2 3.6.2. Example 2
A DHCP server allocates the IPv4 address 192.0.2.2 to a client which A DHCP server allocates the IPv4 address 192.0.2.2 to a client that
included the DHCP client-identifier option data 01:07:08:09:0a:0b:0c included the DHCP client-identifier option data 01:07:08:09:0a:0b:0c
in its DHCP request. The server updates the name "chi.example.com" in its DHCP request. The server updates the name "chi.example.com"
on the client's behalf, and uses the DHCP client identifier option on the client's behalf and uses the DHCP client identifier option
data as input in forming a DHCID RR. The DHCID RDATA is formed by data as input in forming a DHCID RR. The DHCID RDATA is formed by
setting the two type octets to the value 0x0001, the 1-octet digest setting the two type octets to the value 0x0001, the 1-octet digest
type to 1 for SHA-256, and performing a SHA-256 hash computation type to 1 for SHA-256, and performing a SHA-256 hash computation
across a buffer containing the seven octets from the client-id option across a buffer containing the seven octets from the client-id option
and the FQDN (represented as specified in Section 3.5). and the FQDN (represented as specified in Section 3.5).
chi.example.com. A 192.0.2.2 chi.example.com. A 192.0.2.2
chi.example.com. DHCID ( AAEBOSD+XR3Os/0LozeXVqcNc7FwCfQdW chi.example.com. DHCID ( AAEBOSD+XR3Os/0LozeXVqcNc7FwCfQdW
L3b/NaiUDlW2No= ) L3b/NaiUDlW2No= )
If the DHCID RR type is not supported, the RDATA would be encoded If the DHCID RR type is not supported, the RDATA would be encoded
[13] as: [13] as:
\# 35 ( 0001013920fe5d1dceb3fd0ba3379756a70d73b17009f41d58bddbfcd \# 35 ( 0001013920fe5d1dceb3fd0ba3379756a70d73b17009f41d58bddbfcd
6a2503956d8da ) 6a2503956d8da )
3.6.3. Example 3 3.6.3. Example 3
A DHCP server allocating the IPv4 address 192.0.2.3 to a client with A DHCP server allocating the IPv4 address 192.0.2.3 to a client with
Ethernet MAC address 01:02:03:04:05:06 using domain name the Ethernet MAC address 01:02:03:04:05:06 using domain name
"client.example.com" uses the client's link-layer address to identify "client.example.com" uses the client's link-layer address to identify
the client. The DHCID RDATA is composed by setting the two type the client. The DHCID RDATA is composed by setting the two type
octets to zero, the 1-octet digest type to 1 for SHA-256, and octets to zero, the 1-octet digest type to 1 for SHA-256, and
performing an SHA-256 hash computation across a buffer containing the performing an SHA-256 hash computation across a buffer containing the
1-octet 'htype' value for Ethernet, 0x01, followed by the six octets 1-octet 'htype' value for Ethernet, 0x01, followed by the six octets
of the Ethernet MAC address, and the domain name (represented as of the Ethernet MAC address, and the domain name (represented as
specified in Section 3.5). specified in Section 3.5).
client.example.com. A 192.0.2.3 client.example.com. A 192.0.2.3
client.example.com. DHCID ( AAABxLmlskllE0MVjd57zHcWmEH3pCQ6V client.example.com. DHCID ( AAABxLmlskllE0MVjd57zHcWmEH3pCQ6V
skipping to change at page 8, line 37 skipping to change at page 8, line 36
that they have computed, the updater SHOULD conclude that a different that they have computed, the updater SHOULD conclude that a different
client is currently associated with the name in question. The client is currently associated with the name in question. The
updater SHOULD then proceed according to the site's administrative updater SHOULD then proceed according to the site's administrative
policy. That policy might dictate that a different name be selected, policy. That policy might dictate that a different name be selected,
or it might permit the updater to continue. or it might permit the updater to continue.
6. Security Considerations 6. Security Considerations
The DHCID record as such does not introduce any new security problems The DHCID record as such does not introduce any new security problems
into the DNS. In order to obscure the client's identity information, into the DNS. In order to obscure the client's identity information,
a one-way hash is used. And, in order to make it difficult to a one-way hash is used. Further, in order to make it difficult to
'track' a client by examining the names associated with a particular 'track' a client by examining the names associated with a particular
hash value, the FQDN is included in the hash computation. Thus, the hash value, the FQDN is included in the hash computation. Thus, the
RDATA is dependent on both the DHCP client identification data and on RDATA is dependent on both the DHCP client identification data and on
each FQDN associated with the client. each FQDN associated with the client.
However, it should be noted that an attacker that has some knowledge, However, it should be noted that an attacker that has some knowledge,
such as of MAC addresses commonly used in DHCP client identification such as of MAC addresses commonly used in DHCP client identification
data, may be able to discover the client's DHCP identify by using a data, may be able to discover the client's DHCP identify by using a
brute-force attack. Even without any additional knowledge, the brute-force attack. Even without any additional knowledge, the
number of unknown bits used in computing the hash is typically only number of unknown bits used in computing the hash is typically only
48 to 80. 48 to 80.
Administrators should be wary of permitting unsecured DNS updates to Administrators should be wary of permitting unsecured DNS updates to
zones, whether or not they are exposed to the global Internet. Both zones, whether or not they are exposed to the global Internet. Both
DHCP clients and servers SHOULD use some form of update DHCP clients and servers SHOULD use some form of update
authentication (e.g., [12]) when performing DNS updates. authentication (e.g., [12]) when performing DNS updates.
7. IANA Considerations 7. IANA Considerations
IANA is requested to allocate a DNS RR type number for the DHCID IANA has allocated a DNS RR type number for the DHCID record type.
record type.
This specification defines a new number-space for the 2-octet This specification defines a new number-space for the 2-octet
identifier type codes associated with the DHCID RR. IANA is identifier type codes associated with the DHCID RR. IANA has
requested to establish a registry of the values for this number- established a registry of the values for this number-space. Three
space. Three initial values are assigned in Section 3.3, and the initial values are assigned in Section 3.3, and the value 0xFFFF is
value 0xFFFF is reserved for future use. New DHCID RR identifier reserved for future use. New DHCID RR identifier type codes are
type codes are assigned through Standards Action, as defined in [5]. assigned through Standards Action, as defined in [5].
This specification defines a new number-space for the 1-octet digest This specification defines a new number-space for the 1-octet digest
type codes associated with the DHCID RR. IANA is requested to type codes associated with the DHCID RR. IANA has established a
establish a registry of the values for this number-space. Two registry of the values for this number-space. Two initial values are
initial values are assigned in Section 3.4. New DHCID RR digest type assigned in Section 3.4. New DHCID RR digest type codes are assigned
codes are assigned through Standards Action, as defined in [5]. through Standards Action, as defined in [5].
8. Acknowledgements 8. Acknowledgements
Many thanks to Harald Alvestrand, Ralph Droms, Olafur Gudmundsson, Many thanks to Harald Alvestrand, Ralph Droms, Olafur Gudmundsson,
Sam Hartman, Josh Littlefield, Pekka Savola, and especially Bernie Sam Hartman, Josh Littlefield, Pekka Savola, and especially Bernie
Volz for their review and suggestions. Volz for their review and suggestions.
9. References 9. References
9.1. Normative References 9.1. Normative References
[1] Stapp, M. and B. Volz, "Resolution of DNS Name Conflicts Among [1] Stapp, M. and B. Volz, "Resolution of Fully Qualified Domain
DHCP Clients (draft-ietf-dhc-dns-resolution-*)", February 2006. Name (FQDN) Conflicts among Dynamic Host Configuration Protocol
(DHCP) Clients", RFC 4703, October 2006.
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[3] Mockapetris, P., "Domain names - concepts and facilities", [3] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, November 1987. STD 13, RFC 1034, November 1987.
[4] Mockapetris, P., "Domain names - implementation and [4] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
skipping to change at page 11, line 14 skipping to change at page 11, line 14
Authors' Addresses Authors' Addresses
Mark Stapp Mark Stapp
Cisco Systems, Inc. Cisco Systems, Inc.
1414 Massachusetts Ave. 1414 Massachusetts Ave.
Boxborough, MA 01719 Boxborough, MA 01719
USA USA
Phone: 978.936.1535 Phone: 978.936.1535
Email: mjs@cisco.com EMail: mjs@cisco.com
Ted Lemon Ted Lemon
Nominum, Inc. Nominum, Inc.
950 Charter St. 950 Charter St.
Redwood City, CA 94063 Redwood City, CA 94063
USA USA
Email: mellon@nominum.com EMail: mellon@nominum.com
Andreas Gustafsson Andreas Gustafsson
Araneus Information Systems Oy Araneus Information Systems Oy
Ulappakatu 1 Ulappakatu 1
02320 Espoo 02320 Espoo
Finland Finland
Email: gson@araneus.fi EMail: gson@araneus.fi
Intellectual Property Statement Full Copyright Statement
Copyright (C) The Internet Society (2006).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
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This document and the information contained herein are provided on an
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OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
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ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2006). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is provided by the IETF
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