Port Control Protocol (PCP) Anycast Addresses
RFC 7723
| Document | Type |
RFC - Proposed Standard
(January 2016; No errata)
Was draft-ietf-pcp-anycast (pcp WG)
|
|
|---|---|---|---|
| Last updated | 2016-01-22 | ||
| Replaces | draft-kiesel-pcp-ip-based-srv-disc, draft-cheshire-pcp-anycast | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Dave Thaler | ||
| Shepherd write-up | Show (last changed 2015-05-20) | ||
| IESG | IESG state | RFC 7723 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Brian Haberman | ||
| Send notices to | (None) | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) S. Kiesel
Request for Comments: 7723 University of Stuttgart
Category: Standards Track R. Penno
ISSN: 2070-1721 Cisco Systems, Inc.
January 2016
Port Control Protocol (PCP) Anycast Addresses
Abstract
The Port Control Protocol (PCP) anycast addresses enable PCP clients
to transmit signaling messages to their closest PCP-aware on-path
NAT, firewall, or other middlebox without having to learn the IP
address of that middlebox via some external channel. This document
establishes one well-known IPv4 address and one well-known IPv6
address to be used as PCP anycast addresses.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7723.
Copyright Notice
Copyright (c) 2016 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
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Kiesel & Penno Standards Track [Page 1]
RFC 7723 PCP Anycast Addresses January 2016
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. PCP Server Discovery Based on Well-Known IP Address . . . . . 3
2.1. PCP Discovery Client Behavior . . . . . . . . . . . . . . 3
2.2. PCP Discovery Server Behavior . . . . . . . . . . . . . . 3
3. Deployment Considerations . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
4.1. Registration of an IPv4 Special-Purpose Address . . . . . 5
4.2. Registration of an IPv6 Special-Purpose Address . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5.1. Information Leakage through Anycast . . . . . . . . . . . 6
5.2. Hijacking of PCP Messages Sent to Anycast Addresses . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
The Port Control Protocol (PCP) [RFC6887] provides a mechanism to
control how incoming packets are forwarded by upstream devices such
as Network Address and Protocol Translation from IPv6 Clients to IPv4
Servers (NAT64), Network Address Translation from IPv4 to IPv4
(NAT44), and IPv6 and IPv4 firewall devices. Furthermore, it
provides a mechanism to reduce application keepalive traffic
[PCP-OPTIMIZE]. The PCP base protocol document [RFC6887] specifies
the message formats used, but the address to which a client sends its
request is either assumed to be the default router (which is
appropriate in a typical single-link residential network) or has to
be configured otherwise via some external mechanism, such as a
configuration file or a DHCP option [RFC7291].
This document follows a different approach: it establishes two well-
known anycast addresses for the PCP server, one IPv4 address and one
IPv6 address. PCP clients usually send PCP requests to these well-
known addresses if no other PCP server addresses are known or after
communication attempts to such other addresses have failed. The
anycast addresses are allocated from pools of special-purpose IP
addresses (see Section 4), in accordance with Section 3.4 of
[RFC4085]. Yet, a means to disable or override these well-known
addresses (e.g., a configuration file option) should be available in
implementations.
Kiesel & Penno Standards Track [Page 2]
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