IPv6 Maintenance S. Krishnan
Internet-Draft Ericsson
Intended status: Standards Track July 6, 2015
Expires: January 7, 2016
Uplink access technology indications in Router Advertisements
draft-krishnan-6man-uat-00
Abstract
In IPv6 networks Router Advertisements can be used for providing
common configuration information to nodes that are attached. There
are some scenarios where it is advantageous for routers to provide
their uplink access technology information to attached hosts. This
document describes a neighbor discovery option that will allow the
routers to do so.
Status of This Memo
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This Internet-Draft will expire on January 7, 2016.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Internet-Draft Uplink Access Technology Indications in RAs July 2015
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Uplink Access Technology option . . . . . . . . . . . . . . . 3
4. Router Behavior . . . . . . . . . . . . . . . . . . . . . . . 3
5. Host Behavior . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
9. Normative References . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
In several IPv6 networks, the access technology used by routers on
their uplinks is different from that used on their downlinks. There
are some scenarios where it is advantageous for routers to provide
their uplink access technology information to the hosts attached on
the downlinks. One such example is a tethering scenario where a
mobile phone that uses a cellular uplink such as LTE, shares its
internet connection to hosts that connect over a local WiFi link. In
this case it would be beneficial for hosts to know that the uplink
connection is a cellular link and potentially modify their behavior
based on their knowledge. e.g. Application and software updates (and
similar bulk transfers) could be rescheduled based on administrative
configuration.
This document describes an IPv6 Neighbor discovery option [RFC4861]
for routers to advertise their uplink access technology(ies) in a
router advertisement message.
2. Terminology
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].
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3. Uplink Access Technology option
This option is to be carried in RA messages sent out by a router on a
given link. It specifies the uplink type(s) that the router uses.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Uplink Access Technology |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| reserved (set to 0) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
8-bit identifier of the type of option. The option identifier
for the UAT option will be allocated by the IANA.
Length
8-bit unsigned integer. The length of the option (including
the type and length fields) in units of 8 octets. It MUST be
set to 1.
Uplink Access Technology
A 16-bit field that specifies the uplink access technology used
by the router sending the Router Avertisement carrying this
option.
Figure 1: Uplink Access Technology (UAT) Option Layout
Multiple UAT options MAY be present in a single Router Advertisement
message to allow for routers that use multiple uplinks. This
document defines the following initial values for the UAT field that
can be extended by adding new values to the IANA registry.
UAT Access Technology
0x01 3GPP
0x02 DSL
0x03 Cable
0x04 802.3
Figure 2
4. Router Behavior
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The value of the UAT(s) provided in this option can either be
administratively configured or implicitly derived from the access
technology type on the uplink interfaces.
5. Host Behavior
The value of the UAT(s) provided in this option is purely
informational. It helps the hosts gleam additional information about
the router's uplink and perform different actions. Legacy hosts that
do not recognize this option will simply ignore it.
6. Security Considerations
An attacker may attempt to modify the information provided inside
this option to make hosts . These attacks can easily be prevented by
using SeND [RFC3971]
7. IANA Considerations
This document defines a new IPv6 neighbor discovery option for
carrying the uplink access technology type(s). IANA is requested to
create a new registry for storing uplink access technology types and
populate it with the following initial values.
UAT Access Technology Reference
0x01 3GPP [RFC-krishnan-6man-uat-00.txt]
0x02 DSL [RFC-krishnan-6man-uat-00.txt]
0x03 Cable [RFC-krishnan-6man-uat-00.txt]
0x04 802.3 [RFC-krishnan-6man-uat-00.txt]
Figure 3
8. Acknowledgements
TBA.
9. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
Neighbor Discovery (SEND)", RFC 3971, March 2005.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
September 2007.
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Author's Address
Suresh Krishnan
Ericsson
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900 x42871
Email: suresh.krishnan@ericsson.com
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