DHC Working Group S. Jiang
Internet-Draft Huawei Technologies Co., Ltd
Intended status: Standards Track G. Chen
Expires: March 15, 2015 China Mobile
S. Krishnan
Ericsson
R. Asati
Cisco Systems, Inc.
September 11, 2014
Registering Self-generated IPv6 Addresses in DNS using DHCPv6
draft-ietf-dhc-addr-registration-07
Abstract
In networks that are centrally managed, self-generated addresses
cause some traceability issues due to their decentralized nature.
One of the most important issues in this regard is the inability to
register such addresses in DNS. This document defines a mechanism to
register self-generated and statically configured addresses in DNS
through a DHCPv6 server.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Drafts is at http://datatracker.ietf.org/drafts/current/.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 15, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 3
4. DHCPv6 ADDR-REGISTRATION-REQUEST Message . . . . . . . . . . 4
5. DHCPv6 Address Registration Procedure . . . . . . . . . . . . 5
5.1. DHCPv6 Address Registration Request . . . . . . . . . . . 6
5.2. Registration Expiry and Refresh . . . . . . . . . . . . . 6
5.3. Acknowledging Registration and Retransmission . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
In several common network scenarios, IPv6 addresses are self-
generated by the end-hosts by appending a self-generated interface
identifier to a network-specified prefix. Examples of self-generated
addresses include those created using IPv6 Stateless Address
Configuration [RFC4862] , temporary addresses [RFC4941] and
Cryptographically Generated Addresses (CGA) [RFC3972] etc. In
several tightly controlled networks, hosts with self-generated
addresses may face some limitations. One such limitation is related
to the inability of nodes with self-generated addresses to register
their IPv6-address-to-FQDN bindings in DNS. This is related to the
fact that, in such networks, only certain nodes (e.g. The DHCPv6
server) are allowed to update these bindings in order to prevent end-
hosts from registering arbitrary addresses for their FQDNs or
associating their addresses with arbitrary domain names. The
administrators may not want to distribute the address of
authoritative name-server. Also, there is no way to propagate the
address of authoritative name server by any protocols. It is
preferred that the address registration server, which is under the
same management with the authoritative name-server, to know the
address of the authoritative name-server and make registration
requests on behalf of clients. It is preferred by administrators to
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establish and manage one trust relationship between a single DHCPv6
(address registration) server and the DNS authoritative name-server,
rather than to distribute and manage trust relationships between many
clients and the DNS authoritative name-server.
For nodes that obtain their addresses through DHCPv6, a solution has
been specified in [RFC4704]. The solution works by including a
Client FQDN option in the SOLICIT, REQUEST, RENEW or REBIND messages
during the process of acquiring an address through DHCPv6. This
document provides an analogous mechanism to register self-generated
addresses in DNS.
A new ADDR-REGISTRATION-REQUEST DHCPv6 message type is defined to
initiate the address registration request, and two new Status codes
are defined to indicate registration errors on the server side.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Certificate In this document, the term "Certificate" is all referred
to public key certificate.
3. Solution Overview
After successfully assigning a self-generated IPv6 address on one of
its interfaces, an end-host implementing this specification SHOULD
send an ADDR-REGISTRATION-REQUEST message to a DHCPv6 address
registration server. After receiving the address registration
request, the DHCPv6 server registers the IPv6 address to FQDN binding
towards a configured DNS server. An acknowledgement MUST be sent
back to the end host to indicate whether or not the registration
operation succeeded.
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+----+ +-----------+ +---------------+
|Host| |Edge router| |Addr-Reg Server|
+----+ +-----------+ +---------------+
| SLAAC | |
|<--------->| |
| | |
| | ADDR-REGISTRATION-REQUEST |
|-------------------------------------------->|
| | |Register
| | |address
| | Acknowledgment |in DNS
|<--------------------------------------------|
Figure 1: Address Registration Procedure
Furthermore, the registration server MAY apply certain filter/accept
criteria for the address registration requests, particularly for the
client chosen domain names.
It is RECOMMENDED to only set up one address registration server
within an administration domain, although there may be multiple
DHCPv6 servers. While using multiple address registration servers
does potentially increase the load on DNS, because of how [RFC4703]
and [RFC4704] work, this should NOT be an issue - the servers should
work correctly in updating DNS (either adding or removing the
entries). The broken part with multiple servers is the 'extension'
of the registration. If there are two address registration servers
and both receive the initial registration and (correctly) update DNS,
the problem comes when the client extends this but one of the servers
does not receive this extension. Then, the server that missed the
extension removes the entry prematurely (i.e., when it expired
originally).
4. DHCPv6 ADDR-REGISTRATION-REQUEST Message
The DHCPv6 client sends an ADDR-REGISTRATION-REQUEST message to a
server to request an address to be registered in the DNS. The format
of the ADDR-REGISTRATION-REQUEST message is described as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | transaction-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. options .
. (variable) .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
msg-type Identifies the DHCPv6 message type;
Set to ADDR-REGISTRATION-REQUEST (TBA1).
transaction-id The transaction ID for this message exchange.
options Options carried in this message.
DHCPv6 ADDR-REGISTRATION-REQUEST message
The ADDR-REGISTRATION-REQUEST message MUST NOT contain server-
identifier option and MUST contain the IA Address option and the
DHCPv6 FQDN option [RFC4704]. The ADDR-REGISTRATION-REQUEST message
is dedicated for clients to initiate an address registration request
toward an address registration server. Consequently, clients MUST
NOT put any Option Request Option(s) in the ADDR-REGISTRATION-REQUEST
message.
Clients MUST discard any received ADDR-REGISTRATION-REQUEST messages.
Servers MUST discard any ADDR-REGISTRATION-REQUEST messages that meet
any of the following conditions:
o the message does not include a Client Identifier option;
o the message includes a Server Identifier option;
o the message does not include at least one IA Address option;
o the message does not include FQDN option (or include multiple FQDN
options);
o the message includes an Option Request Option.
5. DHCPv6 Address Registration Procedure
The DHCPv6 protocol is used as the address registration protocol when
a DHCPv6 server performs the role of an address registration server.
The DHCPv6 IA Address option [RFC3315] and the DHCPv6 FQDN option
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[RFC4704] are adopted in order to fulfill the address registration
interactions.
5.1. DHCPv6 Address Registration Request
The end-host sends a DHCPv6 ADDR-REGISTRATION-REQUEST message to the
address registration server to the All_DHCP_Relay_Agents_and_Servers
multicast address (ff02::1:2).
The end-host MUST include a Client Identifier option in the ADDR-
REGISTRATION-REQUEST message to identify itself to the server. The
DHCPv6 ADDR-REGISTRATION-REQUEST message MUST contain at least one IA
Address option and exactly one FQDN option. The valid-lifetime field
of the IA Address option MUST be set to the period for which the
client would like to register the binding in DNS.
After receiving this ADDR-REGISTRATION-REQUEST message, the address
registration server MUST register the binding between the provided
FQDN and address(es) in DNS. If the DHCPv6 server does not support
address registration function, it MUST sliently drop the message.
5.2. Registration Expiry and Refresh
For every successful binding registration, the address registration
server MUST record the IPv6-address-to-FQDN bindings and associated
valid-lifetimes in its storage.
The address registration client MUST refresh the registration before
it expires (i.e. before the valid-lifetime of the IA address elapses)
by sending a new ADDR-REGISTRATION-REQUEST to the address
registration server. If the address registration server does not
receive such a refresh after the valid-lifetime has passed, it SHOULD
remove the IPv6-address-to-FQDN bindings in DNS, also the local
record.
It is RECOMMENDED that clients initiate a refresh at about 85% of the
valid-lifetime. Because RAs may periodically 'reset' the valid-
lifetime, the refresh timer MUST be independently maintained from the
address valid-lifetime. Clients SHOULD set a refresh timer to 85% of
the valid-lifetime when they complete a registration operation and
only update this timer if 85% of any updated valid-lifetime would be
sooner than the timer.
5.3. Acknowledging Registration and Retransmission
After an address registration server accepts an address registration
request, it MUST send a Reply message as the response to the client.
The acceptence reply only means that the server has taken
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responsiblity to registry for the client. It may not have actually
completed the update yet. The server is responsible to register all
the addresses in DNS. The server generates a Reply message and
includes a Status Code option with value Success, a Server Identifier
option with the server's DUID, and a Client Identifier option with
the client's DUID.
If there is no reply received within some interval, the client SHOULD
retransmits the message according to section 14 of [RFC3315], using
the following parameters:
o IRT ADDR_REG_TIMEOUT
o MRT ADDR_REG_MAX_RT
o MRC ADDR_REG_MAX_RC
o MRD 0
The below presents a table of values used to describe the message
transmission behavior of clients and servers:
Parameter Default Description
---------------------------------------------------------------------
ADDR_REG_TIMEOUT 1 secs Initial Addr Registration Request timeout
ADDR_REG_MAX_RT 60 secs Max Addr Registration Request timeout value
ADDR_REG_MAX_RC 5 Max Request retry attempts
For each IA Address option in the ADDR-REGISTRATION-REQUEST message
for which the server does not accept its associated registration
request, the server adds an IA Address option with the associated
IPv6 address, and includes a Status Code option with the value
RegistrationDenied (TBA2) in the IA Address option. No other options
are included in the IA Address option.
Upon receiving a RegistrationDenied error status code, the client MAY
also resend the message following normal retransmission routines
defined in [RFC3315] with above parameters. The client MUST wait out
the retransmission time before retrying.
6. Security Considerations
An attacker may attempt to register large number of addresses in
quick succession in order to overwhelm the address registration
server. These attacks may be prevented generic DHCPv6 protection by
using the AUTH option [RFC3315] or Secure DHCPv6
[I-D.ietf-dhc-sedhcpv6].
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7. IANA Considerations
This document defines a new DHCPv6 message, the ADDR-REGISTRATION-
REQUEST message (TBA1) described in Section 4, that requires an
allocation out of the registry of Message Types defined at
http://www.iana.org/assignments/dhcpv6-parameters/
Value Description Reference
-----------------------------------------------------
TBA1 ADDR-REGISTRATION-REQUEST this document
This document defines a new DHCPv6 Status code, the
RegistrationDenied (TBA2) described in Section 5, that requires an
allocation out of the registry of Status Codes defined at
http://www.iana.org/assignments/dhcpv6-parameters/
Code Name Reference
----------------------------------------------------
TBA2 RegistrationDenied this document
8. Acknowledgements
The authors would like to thank Ralph Droms, Ted Lemon, Bernie Volz,
Sten Carlsen, Erik Kline, Lorenzo Colitti, Joel Jaeggli, Sten
Carlsen, Mark Smith, Marcin Siodelski, Darpan Malhotra, Tomek
Mrugalski, Jinmei Tatuya and other members of dhc and v6ops working
groups for their valuable comments.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2136] Vixie, P., Thomson, S., Rekhter, Y., and J. Bound,
"Dynamic Updates in the Domain Name System (DNS UPDATE)",
RFC 2136, April 1997.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, March 2005.
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[RFC4703] Stapp, M. and B. Volz, "Resolution of Fully Qualified
Domain Name (FQDN) Conflicts among Dynamic Host
Configuration Protocol (DHCP) Clients", RFC 4703, October
2006.
[RFC4704] Volz, B., "The Dynamic Host Configuration Protocol for
IPv6 (DHCPv6) Client Fully Qualified Domain Name (FQDN)
Option", RFC 4704, October 2006.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, September 2007.
9.2. Informative References
[I-D.ietf-dhc-sedhcpv6]
Jiang, S., Shen, S., Zhang, D., and T. Jinmei, "Secure
DHCPv6 with Public Key", draft-ietf-dhc-sedhcpv6-03 (work
in progress), June 2014.
Authors' Addresses
Sheng Jiang
Huawei Technologies Co., Ltd
Q14, Huawei Campus
No.156 Beiqing Road
Hai-Dian District, Beijing 100095
P.R. China
Email: jiangsheng@huawei.com
Gang Chen
China Mobile
53A, Xibianmennei Ave., Xuanwu District, Beijing
P.R. China
Phone: 86-13910710674
Email: phdgang@gmail.com
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Suresh Krishnan
Ericsson
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900 x42871
Email: suresh.krishnan@ericsson.com
Rajiv Asati
Cisco Systems, Inc.
7025 Kit Creek road
Research Triangle Park, NC 27709-4987
USA
Email: rajiva@cisco.com
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