ICMPv6 Destination Unreachable due Sleep
Author(s): Teemu Savolainen
A destination node may be unreachable due being in sleep mode that lasts longer than is feasible to buffer a packet in a network or at the last hop entity, such as a router of a link. In...
Internet Engineering Task Force T. Savolainen Internet-Draft Nokia Intended status: Standards Track July 15, 2013 Expires: January 16, 2014 ICMPv6 Destination Unreachable due Sleep draft-savolainen-6man-icmp-destination-sleeping-00 Abstract A destination node may be unreachable due being in sleep mode that lasts longer than is feasible to buffer a packet in a network or at the last hop entity, such as a router of a link. In such scenarios the originator of the packet can be better off knowing destination's sleep being the cause of destination unreachable ICMPv6 message emitted by the entity dropping the packet. This document defines an ICMPv6 Code value for indicating Destination Unreachable due sleep. 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 January 16, 2014. Copyright Notice Copyright (c) 2013 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 Savolainen Expires January 16, 2014 [Page 1] Internet-Draft ICMPv6 destination sleeping July 2013 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. ICMPv6 Destination at Sleep . . . . . . . . . . . . . . . . . 2 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction A destination node may be unreacable due being in a sleep mode that lasts longer than is feasible to buffer a packet, for example by a router of the last hop link. In such cases the originator of the packet that was dropped could benefit from learning more precisely why the packet was dropped. The ICMPv6 [RFC4443] specify codes for indicating destination being unreachable for set of reasons. This document introduces a new code value for indicating destination being at sleep. 1.1. 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 RFC 2119 [RFC 2119]. 2. ICMPv6 Destination at Sleep When a node, such as a router, is unable to deliver an IPv6 packet to a destination while knowing the destination being at sleep, the node SHALL generate ICMPv6 type 1 Destination Unreachable message as defined in RFC4443 [RFC4443] with code value TBD1 "Destination at Sleep". The destination at sleep code is more informative subset of code 3 "Address unreachable". The Code 3 is intended to be used when delivery failure cannot be mapped to other codes defined by RFC4443, such as due "link-specific problem of some sort." (section 3.1 of RFC 4443). Implementations MAY handle the new code similarly to code 3, such as a link-specific problem, in case they do not implement logic specific for handling the destination at sleep error. Savolainen Expires January 16, 2014 [Page 2] Internet-Draft ICMPv6 destination sleeping July 2013 3. Acknowledgements I will ack. 4. IANA Considerations This memo requires IANA to allocate a new ICMPv6 [RFC4443] Code value for TBD1 under the ICMPv6 Type 1 Destination Unreachable. This value is needed to indicate a destination being at sleep. The Code values are registered in the ICMPv6 Parameters registry. The value for "Code" can be the next one available, such as 8. Code Name Reference -------- ---------------------- -------------------- TBD1 Destination at sleep [RFC this document] Table entry for the new Code [TO BE REMOVED: This registration should take place at the following location: http://www.iana.org/assignments/icmpv6-parameters/ icmpv6-parameters.xml#icmpv6-parameters-codes-2 ] 5. Security Considerations Similarly to the ICMPv6 destination port unreachable error, the destination at sleep error reveals existence of a node in a given IPv6 address, and hence can provide useful information for an attacker scanning for existing and connected nodes. However, as the ICMPv6 error message with the new code is sent by other entity than the sleeping node itself, the sleeping node, or a host firewall, has no means for forbidding such messages to be sent. Therefore, if a sleeping node's existence needs to be hidden, which naturally causes benefits of the new error code to be lost, a network firewall has to perform packet filtering. In such case the network has to filter also ICMPv6 address unreachable messages in order for the attacker not being able to derive existence of a node from the lack of address unreachable error message. 6. Normative References [RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC4443, March 2006. Savolainen Expires January 16, 2014 [Page 3] Internet-Draft ICMPv6 destination sleeping July 2013 Author's Address Teemu Savolainen Nokia Hermiankatu 12 D FI-33720 Tampere Finland Email: email@example.com Savolainen Expires January 16, 2014 [Page 4]