Internet Key Exchange Protocol Version 2 (IKEv2) Session Resumption
RFC 5723
Internet Engineering Task Force (IETF) Y. Sheffer
Request for Comments: 5723 Check Point
Category: Standards Track H. Tschofenig
ISSN: 2070-1721 Nokia Siemens Networks
January 2010
Internet Key Exchange Protocol Version 2 (IKEv2)
Session Resumption
Abstract
The Internet Key Exchange version 2 (IKEv2) protocol has a certain
computational and communication overhead with respect to the number
of round trips required and the cryptographic operations involved.
In remote access situations, the Extensible Authentication Protocol
(EAP) is used for authentication, which adds several more round trips
and consequently latency.
To re-establish security associations (SAs) upon a failure recovery
condition is time consuming especially when an IPsec peer (such as a
VPN gateway) needs to re-establish a large number of SAs with various
endpoints. A high number of concurrent sessions might cause
additional problems for an IPsec peer during SA re-establishment.
In order to avoid the need to re-run the key exchange protocol from
scratch, it would be useful to provide an efficient way to resume an
IKE/IPsec session. This document proposes an extension to IKEv2 that
allows a client to re-establish an IKE SA with a gateway in a highly
efficient manner, utilizing a previously established IKE SA.
A client can reconnect to a gateway from which it was disconnected.
The proposed approach encodes partial IKE state into an opaque
ticket, which can be stored on the client or in a centralized store,
and is later made available to the IKEv2 responder for re-
authentication. We use the term ticket to refer to the opaque data
that is created by the IKEv2 responder. This document does not
specify the format of the ticket but examples are provided.
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.
Sheffer & Tschofenig Standards Track [Page 1]
RFC 5723 IKEv2 Session Resumption January 2010
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/rfc5723.
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Sheffer & Tschofenig Standards Track [Page 2]
RFC 5723 IKEv2 Session Resumption January 2010
Table of Contents
1. Introduction ....................................................4
2. Terminology .....................................................5
3. Usage Scenario ..................................................5
4. Protocol Sequences ..............................................7
4.1. Requesting a Ticket ........................................7
4.2. Receiving a Ticket .........................................8
4.3. Presenting a Ticket ........................................9
4.3.1. Prologue ............................................9
4.3.2. IKE_SESSION_RESUME Exchange ........................10
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