Independent Submission Y. Nir
Request for Comments: 6023 Check Point
Category: Experimental H. Tschofenig
ISSN: 2070-1721 NSN
A Childless Initiation of
the Internet Key Exchange Version 2 (IKEv2) Security Association (SA)
This document describes an extension to the Internet Key Exchange
version 2 (IKEv2) protocol that allows an IKEv2 Security Association
(SA) to be created and authenticated without generating a Child SA.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for examination, experimental implementation, and
This document defines an Experimental Protocol for the Internet
community. This is a contribution to the RFC Series, independently
of any other RFC stream. The RFC Editor has chosen to publish this
document at its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not 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
Nir, et al. Experimental [Page 1]RFC 6023 Childless IKEv2 Initiation October 2010Copyright Notice
Copyright (c) 2010 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.
IKEv2, as specified in [RFC5996], requires that the IKE_AUTH exchange
try to create a Child SA along with the IKEv2 SA. This requirement
is sometimes inconvenient or superfluous, as some implementations
need to use IKEv2 for authentication only, while others would like to
set up the IKEv2 SA before there is any actual traffic to protect.
The extension described in this document allows the creation of an
IKEv2 SA without also attempting to create a Child SA. The terms
IKEv2, IKEv2 SA, and Child SA and the various IKEv2 exchanges are
defined in [RFC5996]
An IKEv2 SA without any Child SA is not a fruitless endeavor. Even
without Child SAs, an IKEv2 SA allows:
o Checking the liveness status of the peer via liveness checks.
o Quickly setting up Child SAs without public key operations and
without user interaction.
o Authentication of the peer.
o Detection of NAT boxes between two hosts on the Internet.
1.1. Conventions Used in This Document
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].
Nir, et al. Experimental [Page 2]RFC 6023 Childless IKEv2 Initiation October 20102. Usage Scenarios
Several scenarios motivated this proposal:
o Interactive remote access VPN: the user tells the client to
"connect", which may involve interactive authentication. There is
still no traffic, but some may come later. Since there is no
traffic, it is impossible for the gateway to know what selectors
to use (how to narrow down the client's proposal).
o Location-aware security, as in [SecureBeacon]. The user is
roaming between trusted and untrusted networks. While in an
untrusted network, all traffic should be encrypted, but on the
trusted network, only the IKEv2 SA needs to be maintained.
o An IKEv2 SA may be needed between peers even when there is not
IPsec traffic. Such IKEv2 peers use liveness checks, and report
to the administrator the status of the "VPN links".