Network Working Group C. Donley
Internet-Draft C. Grundemann
Intended status: Informational CableLabs
Expires: September 6, 2012 March 5, 2012
Customer Edge Router Identification Option
draft-donley-dhc-cer-id-option-00
Abstract
Several addressing mechanisms supporting DHCPv6 Prefix Delegation in
home networks require identification of the customer edge router
(CER) as the demarcation between the customer network and the service
provider network. This document reserves a DHCPv6 option to identify
the CER.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3
2. CER Identification Option . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 4
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1. Introduction
Several addressing mechanisms supporting DHCPv6 Prefix Delegation in
home networks such as draft-grundemann-dhcpv6-home-relay require
identification of the customer edge router as the demarcation between
the customer network and the service provider network. For prefix
delegation purposes, it is desirable for other routers within the
home to know which device is the CER so that the customer nome
network only requests a single prefix from the ISP DHCPv6 server, and
efficiently distributes this prefix within the home. This document
reserves a DHCPv6 option to be used to identify the CER.
1.1. Requirements Language
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 RFC 2119 [RFC2119].
2. CER Identification Option
A CER sets the CER_ID to the IPv6 address of its LAN interface. If
it has more than one LAN IPv6 address, it selects one of its LAN or
loopback IPv6 addresses to be used in the CER_ID. An ISP server does
not respond with the CER_ID or sets the CER_ID to ::. Such a
response or lack of response indicates to the DHCPv6 client that it
is the CER.
The format of the CER Identification option is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| CER_ID |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code OPTION_CER_ID (TBD).
option-len 16
CER_ID value IPv6 address of CER or ::
Figure 1.
A DHCPv6 client SHOULD include the CER Identification option code in
an Option Request option [RFC3315] in its DHCP Solicit messages. The
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DHCPv6 server MAY include the CER Identification option in any
response it sends to a client that has included the CER
Identification option code in an Option Request option. The CER
Identification option is sent in the main body of the message to
client, not as a sub-option in, e.g., an IA_NA, IA_TA
[RFC3315]option. When sending the CER Identification option, the
DHCPv6 server MUST set the CER_ID value to either one of its IPv6
addresses or ::. If a device does not receive the CER Identification
Option or receives a CER ID of :: from the DHCPv6 server, it MUST
include one of its Globally Unique IPv6 address(es) in the CER_ID
value in response to DHCPv6 messages received by its DHCPv6 server
that contains the CER Identification option code in an Option Request
option. If the device has only one LAN interface, it SHOULD use its
LAN IPv6 address as the CER_ID value. If the device has more than
one LAN interface, it SHOULD use the lowest Globally Unique address
not assigned to its WAN interface.
3. IANA Considerations
IANA is requested to assign an option code from the "DHCP Option
Codes" Registry for OPTION_CER_ID.
4. Security Considerations
TBD
5. Acknowledgements
6. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 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.
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Authors' Addresses
Chris Donley
CableLabs
858 Coal Creek Cir.
Louisville, CO 80027
US
Email: c.donley@cablelabs.com
Chris Grundemann
CableLabs
858 Coal Creek Cir.
Louisville, CO 80027
US
Email: c.grundemann@cablelabs.com
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