IPv4 and IPv6 Greynets
RFC 6018
| Document | Type |
RFC - Informational
(September 2010; No errata)
Was draft-baker-v6ops-greynet (individual in gen area)
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6018 (Informational) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Ron Bonica | ||
| Send notices to | tjc@ecs.soton.ac.uk | ||
Internet Engineering Task Force (IETF) F. Baker
Request for Comments: 6018 Cisco Systems
Category: Informational W. Harrop
ISSN: 2070-1721 G. Armitage
Swinburne University of Technology
September 2010
IPv4 and IPv6 Greynets
Abstract
This note discusses a feature to support building Greynets for IPv4
and IPv6.
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/rfc6018.
Copyright 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
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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.
Baker, et al. Informational [Page 1]
RFC 6018 IPv4 and IPv6 Greynets September 2010
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. History and Experience . . . . . . . . . . . . . . . . . . 3
2. Deploying Greynets . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Deployment Using Routing - Darknets . . . . . . . . . . . . 4
2.2. Deployment Using Sparse Address Space - Greynets . . . . . 4
2.3. Other Filters . . . . . . . . . . . . . . . . . . . . . . . 6
3. Implications for Router Design . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.1. Normative References . . . . . . . . . . . . . . . . . . . 8
6.2. Informative References . . . . . . . . . . . . . . . . . . 8
1. Introduction
Darknets, also called "Network Telescopes" among other things, have
been deployed by several organizations (including CAIDA, Team Cymru,
and the University of Michigan) to look at traffic directed to
addresses in blocks that are not in actual use. Such traffic becomes
visible by either direct capture (it is routed to a collector) or by
virtue of its backscatter (its resulting in ICMP traffic or
transport-layer resets).
Darknets, of course, have two problems. As their address spaces
become known, attackers stop probing them, so they are less
effective. Also, the administrators of those prefixes are pressured
by Regional Internet Registry (RIR) policy and business requirements
to deploy them in active networks.
[Harrop] defines a 'Greynet' by extension, in these words:
Darknets are often proposed to monitor for anomalous, externally
sourced traffic, and require large, contiguous blocks of unused IP
addresses - not always feasible for enterprise network operators.
We introduce and evaluate the Greynet - a region of IP address
space that is sparsely populated with "darknet" addresses
interspersed with active (or "lit") IP addresses. Based on a
small sample of traffic collected within a university campus
network we saw that relatively sparse greynets can achieve useful
levels of network scan detection.
In other words, instead of setting aside prefixes that an attacker
might attempt to probe and in so doing court discovery, Harrop
proposed that individual (or small groups of adjacent) addresses in
subnets be set aside for the purpose, using different host
identifiers in each subnet to make it more difficult for an address
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