A Widely Deployed Solution to the Generic Routing Encapsulation (GRE) Fragmentation Problem
RFC 7588
Document | Type | RFC - Informational (July 2015; No errata) | |
---|---|---|---|
Authors | Ron Bonica , Carlos Pignataro , Joseph Touch | ||
Last updated | 2015-10-14 | ||
Replaces | draft-bonica-intarea-gre-mtu | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Suresh Krishnan | ||
Shepherd write-up | Show (last changed 2015-03-15) | ||
IESG | IESG state | RFC 7588 (Informational) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Brian Haberman | ||
Send notices to | (None) | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) R. Bonica Request for Comments: 7588 Juniper Networks Category: Informational C. Pignataro ISSN: 2070-1721 Cisco Systems J. Touch USC/ISI July 2015 A Widely Deployed Solution to the Generic Routing Encapsulation (GRE) Fragmentation Problem Abstract This memo describes how many vendors have solved the Generic Routing Encapsulation (GRE) fragmentation problem. The solution described herein is configurable. It is widely deployed on the Internet in its default configuration. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. 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). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see 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/rfc7588. Bonica, et al. Informational [Page 1] RFC 7588 GRE Fragmentation July 2015 Copyright Notice Copyright (c) 2015 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 5 2. Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. RFC 4459 Solutions . . . . . . . . . . . . . . . . . . . 5 2.2. A Widely Deployed Solution . . . . . . . . . . . . . . . 5 3. Implementation Details . . . . . . . . . . . . . . . . . . . 6 3.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2. GRE MTU (GMTU) Estimation and Discovery . . . . . . . . . 6 3.3. GRE Ingress Node Procedures . . . . . . . . . . . . . . . 7 3.3.1. Procedures Affecting the GRE Payload . . . . . . . . 7 3.3.2. Procedures Affecting the GRE Deliver Header . . . . . 8 3.4. GRE Egress Node Procedures . . . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.1. Normative References . . . . . . . . . . . . . . . . . . 10 5.2. Informative References . . . . . . . . . . . . . . . . . 11 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 Bonica, et al. Informational [Page 2] RFC 7588 GRE Fragmentation July 2015 1. Introduction Generic Routing Encapsulation (GRE) [RFC2784] [RFC2890] can be used to carry any network-layer protocol over any network-layer protocol. GRE has been implemented by many vendors and is widely deployed in the Internet. The GRE specification does not describe fragmentation procedures. Lacking guidance from the specification, vendors have developed implementation-specific fragmentation solutions. A GRE tunnel will operate correctly only if its ingress and egress nodes support compatible fragmentation solutions. [RFC4459] describes several fragmentation solutions and evaluates their relative merits. This memo reviews the fragmentation solutions presented in [RFC4459]. It also describes how many vendors have solved the GRE fragmentation problem. The solution described herein is configurable and has been widely deployed in its default configuration. This memo addresses point-to-point unicast GRE tunnels that carryShow full document text