Internet DRAFT - draft-pignataro-intarea-gre-ipv6
draft-pignataro-intarea-gre-ipv6
Intarea Working Group C. Pignataro
Internet-Draft Cisco Systems
Updates: 2784 (if approved) R. Bonica
Intended status: Standards Track Juniper Networks
Expires: April 30, 2015 S. Krishnan
Ericsson
October 27, 2014
IPv6 Support for Generic Routing Encapsulation (GRE)
draft-pignataro-intarea-gre-ipv6-01
Abstract
Generic Routing Encapsulation (GRE) can be used to carry any network
layer protocol over any network layer protocol. GRE procedures are
specified for IPv4, used as either the payload or delivery protocol.
However, GRE procedures are not specified for IPv6, used as either
the payload or delivery protocol.
This document specifies GRE procedures for IPv6, used as either the
payload or delivery protocol, and updates RFC 2784, the original GRE
specification.
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 [RFC2119].
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
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 30, 2015.
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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
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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
2. GRE Header Fields . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Checksum Present . . . . . . . . . . . . . . . . . . . . 3
2.2. Protocol Type . . . . . . . . . . . . . . . . . . . . . . 3
3. IPv6 as a GRE Payload . . . . . . . . . . . . . . . . . . . . 4
4. IPv6 as a GRE Delivery Protocol . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
8. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Generic Routing Encapsulation (GRE) [RFC2784] [RFC2890] can be used
to encapsulate and carry any network layer protocol (payload) over
any network layer protocol (delivery). GRE procedures are specified
for IPv4 [RFC0791], used as either the payload or delivery protocol.
However, GRE procedures are not specified for IPv6 [RFC2460], used as
either the payload or delivery protocol.
This document specifies GRE procedures for IPv6, used as either the
payload or delivery protocol, and updates RFC 2784 [RFC2784].
1.1. Terminology
The following terms are specific to GRE and are modeled from
[RFC2784]:
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o GRE delivery header - an IPv4 or IPv6 header whose source address
represents the GRE ingress node and whose destination address
represents the GRE egress node. The GRE delivery header
encapsulates a GRE header.
o GRE header - the GRE protocol header. The GRE header is
encapsulated by the GRE delivery header and encapsulates GRE
payload.
o GRE payload packet - a network layer packet that needs to be
encapsulated and delivered to some destination, and is
encapsulated by the GRE header.
The following terms are specific MTU discovery:
o path MTU (PMTU) - the minimum MTU of all the links in a path
between a source node and a destination node. If the source and
destination node are connected through equal cost multipath
(ECMP), the PMTU is equal to the minimum link MTU of all links
contributing to the multipath.
o Path MTU Discovery (PMTUD) - A procedure for dynamically
discovering the PMTU between two nodes on the Internet. PMTUD
procedures for IPv6 are defined in [RFC1981].
2. GRE Header Fields
This document does not change any other fields or behaviors of the
GRE specification [RFC2784] [RFC2890].
2.1. Checksum Present
The Checksum Present field SHOULD be set to zero by senders if IPv6
is used as a delivery protocol. Receivers MUST also accept a value
of one in this field and use it to calculate the GRE header length
but they MUST NOT verify the contents of the Checksum field.
2.2. Protocol Type
The Protocol Type field contains the protocol type of the payload
packet. These Protocol Types are defined in [ETYPES]. An
implementation receiving a packet containing a Protocol Type which is
not listed in [ETYPES] SHOULD discard the packet.
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3. IPv6 as a GRE Payload
When the GRE payload is IPv6, the Protocol Type field in the GRE
header MUST be set to 0x86DD.
4. IPv6 as a GRE Delivery Protocol
When the GRE delivery protocol is IPv6, the GRE header can
immediately follow the GRE delivery header. Alternatively, IPv6
extension headers MAY be inserted between the GRE delivery header and
the GRE header. However, the IPv6 Destination Options Header MUST
NOT be inserted between the GRE delivery header and the GRE header.
If the GRE header immediately follows the GRE delivery header, the
Next Header field in the IPv6 header of the GRE delivery packet MUST
be set to the value 47. If extension headers are inserted between
the GRE delivery header and the GRE header, the Next Header field in
the last IPv6 extension header MUST be set to 47.
Following guidance provided in Section 5 of [RFC2460], GRE ingress
nodes SHOULD implement PMTUD, in order to discover and take advantage
of PMTUs greater than the IPv6 required minimum (1280 octets).
However, a GRE ingress node MAY simply restrict itself to sending
packets no larger than 1280 octets, and omit implementation of PMTUD.
5. IANA Considerations
This document makes no request of IANA.
6. Security Considerations
This document adds no additional security risks to GRE, beyond what
is specified in [RFC2784]. It also does not provide any additional
security for GRE.
7. Acknowledgements
The authors would like to thank Fred Baker, Dino Farinacci, and
Andrew Yourtchenko for their thorough review and useful comments.
8. Normative References
[ETYPES] IANA, "ETHER TYPES", 2014,
<http://www.iana.org/assignments/ieee-802-numbers/
ieee-802-numbers.xhtml#ieee-802-numbers-1>.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
1981.
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[RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery
for IP version 6", RFC 1981, August 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
March 2000.
[RFC2890] Dommety, G., "Key and Sequence Number Extensions to GRE",
RFC 2890, September 2000.
Authors' Addresses
Carlos Pignataro
Cisco Systems
7200-12 Kit Creek Road
Research Triangle Park, North Carolina 27709
USA
Email: cpignata@cisco.com
Ron Bonica
Juniper Networks
2251 Corporate Park Drive
Herndon, Virginia
USA
Email: rbonica@juniper.net
Suresh Krishnan
Ericsson
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900 x42871
Email: suresh.krishnan@ericsson.com
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