UCAN BOF B. Carpenter
Internet-Draft Univ. of Auckland
Intended status: Informational May 19, 2014
Expires: November 20, 2014
Autonomic Networking Use Case for Home Networks
draft-carpenter-nmrg-homenet-an-use-case-01
Abstract
This document describes a use case for autonomic networking in home
network scenarios. It is one of a series of use cases intended to
illustrate requirements for autonomic networking.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 2
3. Intended User and Administrator Experience . . . . . . . . . 3
4. Analysis of Parameters and Information Involved . . . . . . . 3
4.1. Parameters each device can decide for itself . . . . . . 4
4.2. Information needed from policy intent . . . . . . . . . . 4
5. Interaction with other devices . . . . . . . . . . . . . . . 5
5.1. Information needed from neighbor devices . . . . . . . . 5
5.2. Monitoring, diagnostics and reporting . . . . . . . . . . 6
6. Comparison with current solutions . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
10. Change log [RFC Editor: Please remove] . . . . . . . . . . . 7
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
This document is one of a set of use cases being developed to clarify
the requirements for discovery and negotiation protocols for
autonomic networking (AN). The background to AN is described in
[I-D.irtf-nmrg-autonomic-network-definitions] and
[I-D.irtf-nmrg-an-gap-analysis]. A problem statement and outline
requirements for the negotiation protocol are given in
[I-D.jiang-config-negotiation-ps].
Note in draft: The format of this document may be modified as we
agree on a common format for AN use cases. In particular, opinions
may vary about how concrete vs how abstract a use case should be.
2. Problem Statement
The use case considered here is autonomic operation of home networks
based on IPv6, in general accordance with [I-D.ietf-homenet-arch].
The model assumes that a typical homenet in the future will have
multiple network segments, several routers, and a reasonably large
number of hosts, but no expert human manager. For some aspects of
homenet configuration, a protocol solution known as HNCP (homenet
control protocol) has been designed and implemented
[I-D.ietf-homenet-hncp]. A solution has also been described for
bootstrapping trust in a homenet
[I-D.behringer-homenet-trust-bootstrap].
Additional issues that impact homenet configuration are discussed in
[I-D.winters-homenet-sper-interaction],
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[I-D.pfister-homenet-prefix-assignment],
[I-D.mglt-homenet-naming-architecture-dhc-options] and
[I-D.stenberg-homenet-dnssd-hybrid-proxy-zeroconf].
The problem to be solved by AN is how to replace these and other
partial solutions by a generic solution that sets all necessary
parameters for the homenet to operate efficiently, reliably and
securely, with minimal human intervention and without the need for
traditional top-down configuration.
It should be noted that HNCP has a quite generic design, but so far
has been described for a fairly narrow scope of application, and
other aspects of homenet bootstrapping, discovery and configuration
are currently handled by other methods. The present draft takes no
position on these various solutions, since its goal is only to
describe the use case.
This use case does not currently consider the challenges posed by
multiple provisioning domains as defined by [I-D.ietf-mif-mpvd-arch].
3. Intended User and Administrator Experience
In a homenet, the basic assumption is that no human involved has
technical knowledge beyond the ability to unwrap a product, connect a
few cables, and follow simple instructions. Indeed, the parody "Have
you tried turning it off and on again?" may apply literally.
Therefore, the desired user experience is that everything just works,
that there are no mandatory user actions, and that no specialist
knowledge is needed. If any user choices are offered, there must be
a reasonable default. When power failures or equipment failures
occur, recovery to the best possible running state must be automatic.
If any diagnostic messages are produced, they must be simple and
clear, and of course provided in the user's own language. If any
logs are recorded, it is to be expected that the normal user will
never look at them and could not understand them.
4. Analysis of Parameters and Information Involved
Numerous parameters are involved in a homenet (some of them can of
course be pre-configured with default values). They include:
o Identity of a trust anchor to act as a local certification
authority (CA) and registration authority (RA) for nodes inside
the homenet.
o Identity of border devices (equivalent to perimeter
identification).
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o Firewall rules (for border devices and for host firewalls).
o IP address prefix(es) for the whole homenet.
o Individual prefix(es) for each subnet.
o Choice of routing protocol.
o Initial configuration of all routers.
o Default router for each subnet.
o Rules for address selection.
o Local namespace information (delegated zone if any, etc.).
o DNS server(s).
4.1. Parameters each device can decide for itself
This section identifies those of the above parameters that do not
need external information in order for the devices concerned to set
them to a reasonable value after bootstrap or after a network
disruption. There are few of these:
o Default firewall rules for hosts. Hosts should be shipped from
the manufacturer with generally applicable default firewall rules.
o Default rules for address selection should conform to [RFC6724].
4.2. Information needed from policy intent
This section identifies those parameters that need external
information about policy intent in order for the devices concerned to
set them. to a non-default value. It's assumed that in a homenet,
policy intent will likely be provided by the main homenet router, and
may itself be a default setting in that router, since there is
normally no human expert to set policy. Not all devices will need to
know all of these intents.
o Method of determining the trust anchor.
o Whether firewall rules will be changed from their default
settings.
o Whether more than one GUA prefix will be deployed.
o Whether a ULA prefix will be deployed.
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o Which routing protocol is preferred.
o Whether DHCPv6 will be deployed.
o Whether non-default rules for address selection will be deployed.
o Whether IPv4 and DHCP will be deployed (IPv6 is assumed).
5. Interaction with other devices
5.1. Information needed from neighbor devices
This section identifies those of the above parameters that need
external information from neighbor devices (such as other routers) in
order for the devices concerned to set them. In many cases, two-way
dialogue with neighbor devices is needed to set or optimise them.
o Identity of a trust anchor.
o Routers will need to discover their neighbors.
o Routers will need to determine whether they are border devices.
o Border routers will need to apply a default border firewall
policy; interior routers will not be firewalls by default.
o Hosts may need to acquire a non-default firewall policy.
o Border routers will need to determine the IP address prefix(es)
for the whole homenet.
o One border router will need to generate the ULA prefix for the
whole homenet.
o Routers will need to discover the network topology and then to
apply a prefix delegation method to deliver at least one prefix to
each subnet.
o With knowledge of its neighbors and after prefix delegation, each
router will need to configure and launch the agreed routing
protocol.
o Hosts need to acquire a default router for each interface.
o Hosts may need to acquire non-default rules for address selection.
o The local namespace service must configure itself. Relevant
devices will need to know at least the zone name delegated to the
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homenet. This is a complex topic, so the reader is referred to
drafts that already describe the needed functions:
[I-D.mglt-homenet-naming-architecture-dhc-options] and
[I-D.stenberg-homenet-dnssd-hybrid-proxy-zeroconf].
o Hosts need to acquire DNS server address(es).
5.2. Monitoring, diagnostics and reporting
This section discusses what role devices should play in monitoring,
fault diagnosis, and reporting.
o In general, failure to successfully set reasonable values for any
network parameter should be logged and notified to the user, in
simple, non-technical words in the user's own language.
o Similarly, hard failures should be logged and notified, even if
the network has somehow routed around them.
o Users are very unlikely to take an interest in warnings of any
kind, so they are probably a waste of time.
o Firewall incidents are typically logged in a proprietary fashion.
It would be conceivable for all firewalls in a homenet to log
incidents centrally but it seems unlikely that such a feature
would ever be used by a typical home user.
6. Comparison with current solutions
This section briefly compares the above use case with current
solutions. Today's typical single-router homenets do largely run
without significant human intervention, relying on fixed DHCP setups
for IPv4 and on out-of-the-box Router Advertisements for IPv6. This
comparison is not very illuminating, since we are interested in
complex homenets with multiple routers. A better comparison is with
the emerging prototype homenet environment based on the various
drafts cited in Section 2. The functionality described is very
similar. The actual content of the messages would also be very
similar to those in HNCP etc. However, using a generic autonomic
discovery and negotiation protocol instead of a mixture of dedicated
solutions has the advantage that additional parameters can be
included in the autonomic solution without creating new mechanisms.
This is the principal argument for a generic approach.
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7. Security Considerations
Relevant security issues are discussed in
[I-D.irtf-nmrg-autonomic-network-definitions],
[I-D.jiang-config-negotiation-ps] and [I-D.ietf-homenet-arch]. The
security specificity of a homenet is the need to establish a trust
anchor in the absence of a human expert, which will allow remaining
security features to configure themselves autonomically.
8. IANA Considerations
This document requests no action by IANA.
9. Acknowledgements
Valuable comments were received from Steven Barth, Michael Behringer,
Sheng Jiang, Mark Townsley, and others.
This document was produced using the xml2rfc tool [RFC2629].
10. Change log [RFC Editor: Please remove]
draft-carpenter-nmrg-homenet-an-use-case-01: clarifications, more
accurate characterisation of HNCP, 2014-05-19.
draft-carpenter-nmrg-homenet-an-use-case-00: original version,
2014-04-10.
11. References
[I-D.behringer-homenet-trust-bootstrap]
Behringer, M., Pritikin, M., and S. Bjarnason,
"Bootstrapping Trust on a Homenet", draft-behringer-
homenet-trust-bootstrap-02 (work in progress), February
2014.
[I-D.ietf-homenet-arch]
Chown, T., Arkko, J., Brandt, A., Troan, O., and J. Weil,
"IPv6 Home Networking Architecture Principles", draft-
ietf-homenet-arch-13 (work in progress), March 2014.
[I-D.ietf-homenet-hncp]
Stenberg, M. and S. Barth, "Home Networking Control
Protocol", draft-ietf-homenet-hncp-00 (work in progress),
April 2014.
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[I-D.ietf-mif-mpvd-arch]
Anipko, D., "Multiple Provisioning Domain Architecture",
draft-ietf-mif-mpvd-arch-01 (work in progress), May 2014.
[I-D.irtf-nmrg-an-gap-analysis]
Behringer, M., Carpenter, B., and S. Jiang, "Gap Analysis
for Autonomic Networking", draft-irtf-nmrg-an-gap-
analysis-00 (work in progress), April 2014.
[I-D.irtf-nmrg-autonomic-network-definitions]
Behringer, M., Pritikin, M., Bjarnason, S., Clemm, A.,
Carpenter, B., Jiang, S., and L. Ciavaglia, "Autonomic
Networking - Definitions and Design Goals", draft-irtf-
nmrg-autonomic-network-definitions-00 (work in progress),
December 2013.
[I-D.jiang-config-negotiation-ps]
Jiang, S., Yin, Y., and B. Carpenter, "Network
Configuration Negotiation Problem Statement and
Requirements", draft-jiang-config-negotiation-ps-02 (work
in progress), January 2014.
[I-D.mglt-homenet-naming-architecture-dhc-options]
Migault, D., Cloetens, W., Griffiths, C., and R. Weber,
"DHCP Options for Homenet Naming Architecture", draft-
mglt-homenet-naming-architecture-dhc-options-01 (work in
progress), February 2014.
[I-D.pfister-homenet-prefix-assignment]
Pfister, P., Paterson, B., and J. Arkko, "Prefix and
Address Assignment in a Home Network", draft-pfister-
homenet-prefix-assignment-01 (work in progress), May 2014.
[I-D.stenberg-homenet-dnssd-hybrid-proxy-zeroconf]
Stenberg, M., "Auto-Configuration of a Network of Hybrid
Unicast/Multicast DNS-Based Service Discovery Proxy
Nodes", draft-stenberg-homenet-dnssd-hybrid-proxy-
zeroconf-00 (work in progress), February 2014.
[I-D.winters-homenet-sper-interaction]
Winters, T., "Service Provider Edge Router Interaction",
draft-winters-homenet-sper-interaction-01 (work in
progress), February 2014.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
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[RFC6724] Thaler, D., Draves, R., Matsumoto, A., and T. Chown,
"Default Address Selection for Internet Protocol Version 6
(IPv6)", RFC 6724, September 2012.
Author's Address
Brian Carpenter
Department of Computer Science
University of Auckland
PB 92019
Auckland 1142
New Zealand
Email: brian.e.carpenter@gmail.com
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