< draft-wkumari-dhc-capport-02.txt   draft-wkumari-dhc-capport-03.txt >
Network Working Group W. Kumari Network Working Group W. Kumari
Internet-Draft Google Internet-Draft Google
Intended status: Informational O. Gudmundsson Intended status: Informational O. Gudmundsson
Expires: October 18, 2014 Shinkuro Inc. Expires: December 3, 2014 Shinkuro Inc.
P. Ebersman P. Ebersman
Infoblox Infoblox
S. Sheng S. Sheng
ICANN ICANN
April 16, 2014 June 1, 2014
Captive-Portal identification in DHCP / RA Captive-Portal identification in DHCP / RA
draft-wkumari-dhc-capport-02 draft-wkumari-dhc-capport-03
Abstract Abstract
In many environments (such as hotels, coffee shops and other In many environments (such as hotels, coffee shops and other
establishments that offer Internet service to customers), it is establishments that offer Internet service to customers), it is
common to start new connections in a captive portal mode, i.e. highly common to start new connections in a captive portal mode, i.e. highly
restrict what the customer can do until the customer has accepted restrict what the customer can do until the customer has accepted
terms of service, provided payment information or authenticated. terms of service, provided payment information or authenticated.
This document describes a DHCP option (and an RA extension) to inform This document describes a DHCP option (and an RA extension) to inform
skipping to change at page 1, line 43 skipping to change at page 1, line 43
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 18, 2014. This Internet-Draft will expire on December 3, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3
2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. DNS Redirection . . . . . . . . . . . . . . . . . . . . . 3 2.1. DNS Redirection . . . . . . . . . . . . . . . . . . . . . 3
2.2. HTTP Redirection . . . . . . . . . . . . . . . . . . . . 4 2.2. HTTP Redirection . . . . . . . . . . . . . . . . . . . . 4
2.3. IP Hijacking . . . . . . . . . . . . . . . . . . . . . . 4 2.3. IP Hijacking . . . . . . . . . . . . . . . . . . . . . . 4
3. The Captive-Portal DHCP Option . . . . . . . . . . . . . . . 4 3. The Captive-Portal DHCP Option . . . . . . . . . . . . . . . 4
4. The Captive-Portal RA Option . . . . . . . . . . . . . . . . 5 4. The Captive-Portal RA Option . . . . . . . . . . . . . . . . 5
5. Use of the Captive-Portal Option . . . . . . . . . . . . . . 6 5. Use of the Captive-Portal Option . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 9 9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9 9.2. Informative References . . . . . . . . . . . . . . . . . 8
Appendix A. Changes / Author Notes. . . . . . . . . . . . . . . 9 Appendix A. Changes / Author Notes. . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
In many environments (coffee shops and hotels), users need to connect In many environments users need to connect to a captive portal device
to a captive portal device and agree to an acceptable use policy or and agree to an acceptable use policy or provide billing information
provide billing information before they can access the Internet. before they can access the Internet.
In order to present the user with the captive portal web page, many In order to present the user with the captive portal web page, many
devices perform DNS and / or HTTP and / or IP hijacks. As well as devices perform DNS and / or HTTP and / or IP hijacks. As well as
being kludgy hacks, these techniques looks very similar to attacks being kludgy hacks, these techniques looks very similar to attacks
that DNSSEC and TLS protect against. that DNSSEC and TLS protect against. This makes the user experience
sub-optimal.
This document describes a DHCP option (Captive-Portal) that informs This document describes a DHCP option (Captive-Portal) and IPv6
DHCP clients that they are behind a captive portal device, and how to Router Advertisement (RA) extension that informs clients that they
contact it. are behind a captive portal device, and how to contact it.
This document neither condones nor condemns captive portals; instead This document neither condones nor condemns captive portals; instead
it recognises that they are here to stay, and attempts to improve the it recognises that they are here to stay, and attempts to improve the
user's experience. user's experience.
1.1. Requirements notation 1.1. Requirements notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2. Background 2. Background
Many Internet Service Providers (ISPs) that offer public Internet Many Internet Service Providers (ISPs) that offer public Internet
access require the user to first accept an Acceptable Use Policy access require the user to first accept an Acceptable Use Policy
(AUP) and / or provides billing information (such as their last name (AUP) and / or provides billing information (such as their last name
and / or room number in a hotel, credit card information, etc) and room number in a hotel, credit card information, etc.) through a
through a web interface. web interface.
In order to meet this requirement, some ISPs implement a captive In order to meet this requirement, some ISPs implement a captive
portal (CP) - a system that intercepts user requests and redirects portal (CP) - a system that intercepts user requests and redirects
them to an interstitial login page. them to an interstitial login page.
Captive portals intercept and redirects user requests in a number of Captive portals intercept and redirects user requests in a number of
ways, including: ways, including:
o DNS Redirection o DNS Redirection
o IP Redirection o IP Redirection
o HTTP Redirection o HTTP Redirection
o Restricted scope addresses o Restricted scope addresses
o Traffic blocking (until the user is authenticated) o Traffic blocking (until the user is authenticated)
In order to ensure that the user is unable to access the Internet, In order to ensure that the user is unable to access the Internet
captive portals usually implement IP based filters, or place the user until they have satisfied the requirements, captive portals usually
in to a restricted VLAN or restricted IP range until after they have implement IP based filters, or place the user in to a restricted VLAN
been authorized. (or restricted IP range) until after they have been authorized.
2.1. DNS Redirection 2.1. DNS Redirection
The CP either intercepts all DNS traffic or advertises itself (for The CP either intercepts all DNS traffic or advertises itself (for
example using DHCP) as the recursive server for the network. Until example using DHCP) as the recursive server for the network. Until
the user has authenticated to the captive portal, the CP responds to the user has authenticated to the captive portal, the CP responds to
all DNS requests listing the address of its web portal. Once the all DNS requests listing the address of its web portal. Once the
user has authenticated the CP returns the "correct" addresses. user has authenticated the CP returns the "correct" addresses.
This technique has many shortcomings. It fails if the client is This technique has many shortcomings. It fails if the client is
performing DNSSEC validation, or if the client already has the DNS performing DNSSEC validation, is running their own resolver, or
information cached. already has the DNS information cached.
2.2. HTTP Redirection 2.2. HTTP Redirection
In this implementation, the CP acts like a transparent HTTP proxy; In this implementation, the CP acts like a transparent HTTP proxy;
but when it sees an HTTP request from an unauthenticated client, it but when it sees an HTTP request from an unauthenticated client, it
intercepts the request and responds with an HTTP status code 302 to intercepts the request and responds with an HTTP status code 302 to
redirect the client to the Captive Portal Login. redirect the client to the Captive Portal Login.
The issues with this technique include: This technique has a number of issues, including:
o It fails if the user is only using HTTPS o It fails if the user is only using HTTPS.
o It exposes various private user information, such as HTTP Cookies, o It exposes various private user information, such as HTTP Cookies,
etc. etc.
o It doesn't work if the client has a VPN and / or proxies their web o It doesn't work if the client has a VPN and / or proxies their web
traffic to an external web proxy. traffic to an external web proxy.
2.3. IP Hijacking 2.3. IP Hijacking
In this scenario, the captive portal intercepts connections to any IP In this scenario, the captive portal intercepts connections to any IP
address. It spoofs the destination IP address and "pretends" to be address. It spoofs the destination IP address and "pretends" to be
whatever the user tried to access. whatever the user tried to access.
This technique has similar issues as the HTTP solution, but may also This technique has similar issues as the HTTP solution, but may also
break other protocols, and may expose more of the users private break other protocols, and may expose more of the users private
information, etc. information.
3. The Captive-Portal DHCP Option 3. The Captive-Portal DHCP Option
The Captive Portal DHCP Option (TBA1) informs the DHCP client that it The Captive Portal DHCP Option (TBA1) informs the DHCP client that it
is behind a captive portal and provides the URI to access the is behind a captive portal and provides the URI to access the
authentication page. This is primarily intended to improve the user authentication page. This is primarily intended to improve the user
experiance; for the forseeable future captive portals will still need experience; for the foreseeable future captive portals will still
to implement the interception techniques to serve legacy clinets. need to implement the interception techniques to serve legacy
clients.
This draft is not intended to provide guidance on how to implement a
captive portal. As such, it assumes that the captive portal on a
dual-stack or IPv6-only network is already capable of intercepting
IPv6 traffic. However, in order to support IPv6 with the proposed
DHCP option, there are some additional considerations. In a dual-
stack network, the network supports both IPv4 and IPv6 protocols
simultaneously, but can have a mix of IPv4-only, IPv6-only, and dual-
stack devices using the network, meaning that it may be necessary to
have parallel notifications via DHCPv4 and DHCPv6.
IPv4-only and dual-stack devices can technically both support
receiving the option via DHCPv4, but dual-stack implementations would
need to ensure that the correct action would be taken for both IPv4
and IPv6 traffic despite only receiving an option via IPv4. For
devices/networks that only speak IPv6, and to avoid this dependency
on the implementation, a DHCPv6 option is necessary.
[ED NOTE:] This is complicated by the fact that not all devices
support DHCPv6, and thus it may be necessary to investigate other
methods to notify IPv6-only devices of a captive portal. Since this
option is only intended to help clients gracefully deal with networks
that have a captive portal, it may be acceptable to note that if a
client does not support DHCPv6, it simply won't be able to take
advantage of this optimization, but will otherwise function normally.
[/note]
The format of the DHCP Captive-Portal DHCP option is identical for The format of the DHCP Captive-Portal DHCP option is shown below.
both DHCPv4 and DHCPv6 and is shown below.
Code Len Data Code Len Data
+------+------+------+------+------+-- --+-----+ +------+------+------+------+------+-- --+-----+
| code | len | URI ... | | code | len | URI ... |
+------+------+------+------+------+-- --+-----+ +------+------+------+------+------+-- --+-----+
o Code: The Captive-Portal DHCP Option (TBA1 for DHCPv4, TBA2 for o Code: The Captive-Portal DHCP Option (TBA1 for DHCPv4, TBA2 for
DHCPv6) DHCPv6)
o Len: The length, in octets of the URI. o Len: The length, in octets of the URI.
o URI: The URI of the authentication page that the user should o URI: The URI of the authentication page that the user should
connect to. connect to.
The URI MUST be a URL with an IP-literal for the host portion (to The URI MUST be a URL with an IP-literal for the host portion (to
remove the need to allow DNS from unauthenticated clients). The remove the need to allow DNS from unauthenticated clients). The
DHCPv4 URI MUST contain an IPv4 address, and the DHCPv6 URI MUST DHCPv4 URI MUST contain an IPv4 address.
contain an IPv6 address (to account for IPv4 only or IPv6 only
capable devices - not everyting is dual stack!)
[ED NOTE: Using an address literal is less than ideal, but better [ED NOTE: Using an address literal is less than ideal, but better
than the alternatives. Recommending a DNS name means that the CP than the alternatives. Recommending a DNS name means that the CP
would need to allow DNS from unauthenticated clients (as we don't would need to allow DNS from unauthenticated clients (as we don't
want to force users to use the CP's provided DNS) and some folk would want to force users to use the CP's provided DNS) and some folk would
use this to DNS Tunnel out. This would make the CP admin block use this to DNS Tunnel out. This would make the CP admin block
external recursives).] external recursives).]
4. The Captive-Portal RA Option 4. The Captive-Portal RA Option
[ Ed: I'm far from an RA expert, but it was suggested that we shold [ Ed: I'm far from an RA expert. I think there are only 8 bits for
advertize this via RA as well as DHCP. I think there are only 8 bits Type, is it worth burning an option code on this? I have also
for Type, is it worth burning an option code on this? I have also
specified that the option length should padded to multiples of 8 byte specified that the option length should padded to multiples of 8 byte
to better align with the examples I've seen (and I'm on a plane so to better align with the examples I've seen. Is this required /
cannot easily search for more!) Is this required / preferred, or is preferred, or is smaller RAs better? ]
smaller RAs better? ]
This section describes the Captive-Portal Router Advertisement This section describes the Captive-Portal Router Advertisement
option. option.
0 1 2 3 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 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 | URI . | Type | Length | URI .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ .
. . . .
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Captive-Portal RA Option Format Figure 2: Captive-Portal RA Option Format
Type TBA3 Type TBA3
Length 8-bit unsigned integer. The length of the option (including Length 8-bit unsigned integer. The length of the option (including
the Type and Length fields) in units of 8 bytes. the Type and Length fields) in units of 8 bytes.
URI The URI of the authentication page that the user should connect URI The URI of the authentication page that the user should connect
to. This should be padded with NULL (0x0) to make the total to. This should be padded with NULL (0x0) to make the total
option length (including the Type and Length fields) a mutliple of option length (including the Type and Length fields) a multiple of
8 bytes. 8 bytes.
5. Use of the Captive-Portal Option 5. Use of the Captive-Portal Option
[ED NOTE: This section is, and probably will remain, fairly hand [ED NOTE: This section is, and probably will remain, fairly hand
wavy. This option provides notice to the OS / User applications that wavy. This option provides notice to the OS / User applications that
there is a CP, but I think that the UI / etc is best designed / there is a CP, but I think that the UI / etc is best designed /
handled by the Operating System vendors / Application developers. ] handled by the Operating System vendors / Application developers. ]
The purpose of the Captive-Portal Option is to inform the operating The purpose of the Captive-Portal Option is to inform the operating
system and applications that they are behind a captive portal type system and applications that they are behind a captive portal type
device and will need to authenticate before getting network access device and will need to authenticate before getting network access
(and how to reach the authentication page). (and how to reach the authentication page). What is done with this
information is left up to the operating system and application
The Captive-Portal Option is defined for IPv6 RAs and IPv6 DHCP and vendors. This document provides a very high level example of what
IPv4 DHCP. The URIs in these SHOULD all be the same, but if they are could be done with this information.
not, the precedence is as follows:
1. IPv6 DHCP (most preferred)
2. IPv4 DHCP
3. IPv6 RA (least preferred)
This preference was chosen because an IPv6 capable client machine
will first get an IP address (and possibly the Captive-Portal option)
via RA, and will then get additional information via DHCP v6. The
client is not fully configured until it has completed the DHCP step,
and so this is "newer" information. The DHCP v4 preference is in the
middle, because it is likely that this will be delpoyed first on many
captive portals. Once IPv6 is deployed, we don't want legacy
(forgotten!) configuration to override the "newer" configuration
information. [Ed: This ordering is somewhat arbritary, as is the
justification, but there should be *some* standard and this seemed as
good as any! ]
The exact method that the interaction with the user occurs is device
/ operating system / application dependent. The below is simply one
option.
When the device receives a DHCP response with the Captive-Portal When the device discovers that it is behind a captive portal it
Option it SHOULD: SHOULD:
1. Not initiate new IP connections until the CP has been satisfied. 1. Not initiate new IP connections until the CP has been satisfied
Existing connections should be quiesced. This will happen more (other than those to the captive portal page and connectivity
often than some expect -- you buy 1h of Internet at a cafe and checks). Existing connections should be quiesced (this will
stay there for 3h -- this will "interrupt" you a few times). happen more often than some expect -- you buy 1h of Internet at a
cafe and stay there for 3h -- this will "interrupt" you a few
times).
2. Present a dialog box to the user informing that they are behind a 2. Present a dialog box to the user informing them hat they are
captive portal and ask if they wish to proceed. behind a captive portal and ask if they wish to proceed.
3. If the user elects to proceed, the device should initiate a 3. If the user elects to proceed, the device should initiate a
connection to the captive portal login page using a web browser connection to the captive portal login page using a web browser
configured with a separate cookie store. Some captive portals configured with a separate cookie store. Some captive portals
send the user a cookie when they authenticate (so that the user send the user a cookie when they authenticate (so that the user
can re-authenticate more easily in the future - the browser can re-authenticate more easily in the future - the browser
should keep these CP cookies separate from other cookies. should keep these CP cookies separate from other cookies.
4. Once the user has authenticated (how does it know? HTTP 4. Once the user has authenticated normal IP connectivity should
response?! Probe (ugh?)) normal IP connectivity should resume. resume. This document does not define how to know that the user
has authenticated [ Ed: Should it? And option would be for the
"Thank you for paying" page to contain a unique string (e.g:
"CP_SATISFIED" ]. Operating system vendors may wish to provide a
public service that their devices can use as a connectivity
check.
5. The device should (using an OS dependent method) expose to the 5. The device should (using an OS dependent method) expose to the
user / user applications that they have connected though a user / user applications that they have connected though a
captive portal (for example by creating a file in /proc/net/ captive portal (for example by creating a file in /proc/net/
containing the interface and captive portal URI). This should containing the interface and captive portal URI). This should
continue until the network changes, or a new DHCP message without continue until the network changes, or a new DHCP message without
the CP is received. the CP is received.
6. IANA Considerations 6. IANA Considerations
This document defines DHCPv4 Captive-Portal option which requires This document defines DHCPv4 Captive-Portal option which requires
assignment of DHCPv4 option code TBA1 assigned from "Bootp and DHCP assignment of DHCPv4 option code TBA1 assigned from "Bootp and DHCP
options" registry (http://www.iana.org/assignments/ bootp-dhcp- options" registry (http://www.iana.org/assignments/ bootp-dhcp-
parameters/bootp-dhcp-parameters.xml), as specified in [RFC2939]. parameters/bootp-dhcp-parameters.xml), as specified in [RFC2939].
The IANA is requested to also assign an option codes for the DHCPv6
Captive-Portal (TBA2) option from the "DHCPv6 and DHCPv6 options"
registry (http:// www.iana.org/assignments/dhcpv6-parameters/
dhcpv6-parameters.xml).
The IANA is also requested at assign an IPv6 RA Type code (TBA3) from The IANA is also requested at assign an IPv6 RA Type code (TBA3) from
the [TODO] registry. Thanks IANA! the [TODO] registry. Thanks IANA!
7. Security Considerations 7. Security Considerations
An attacker with the ability to inject DHCP messages could include An attacker with the ability to inject DHCP messages could include
this option and so force users to contact him. As an attacker with this option and so force users to contact an address of his choosing.
this capability could simply list himself as the default gateway (and As an attacker with this capability could simply list himself as the
so see all the victim's traffic), we do not think this gives them default gateway (and so intercept all the victim's traffic), this
significantly more capabilities. Fake DHCP servers / fake RAs are does not provide them with significantly more capabilities. Fake
currently a security concern - this doesn't make them any better or DHCP servers / fake RAs are currently a security concern - this
worse. doesn't make them any better or worse.
Devices and systems that automatically connect to open network could Devices and systems that automatically connect to open network could
potentially be tracked using the techniques described in this potentially be tracked using the techniques described in this
document (forcing the user to continually authenticate, or exposing document (forcing the user to continually authenticate, or exposing
their browser fingerprint), but similar tracking could already be their browser fingerprint), but similar tracking could already be
performed with the standard captive portal mechanisms, so this performed with the standard captive portal mechanisms, so this
doesn't seem to give the attackers more capabilities. doesn't seem to give the attackers more capabilities.
By simplifying the interaction with the captive portal systems, and By simplifying the interaction with the captive portal systems, and
doing away with the need for interception, we think that users will doing away with the need for interception, we think that users will
be less likely to disable useful security safeguards like DNSSEC be less likely to disable useful security safeguards like DNSSEC
validation, VPNs, etc. validation, VPNs, etc. In addition, because the system knows that it
is behind a captive portal it can know not to send cookies,
credentials, etc.
8. Acknowledgements 8. Acknowledgements
The primary author has discussed this idea with a number of folk, and The primary author has discussed this idea with a number of folk, and
asked them to assist by becoming co-authors. Unfortunately he has asked them to assist by becoming co-authors. Unfortunately he has
forgotten who many of them were; if you were one of them, I forgotten who many of them were; if you were one of them, I
apologize. apologize.
Thanks to Vint Cerf for the initial idea / asking me to write this. Thanks to Vint Cerf for the initial idea / asking me to write this.
Thanks to Wes George for supplying the v6 text. Thanks to Wes George for supplying the v6 text. Thanks to Lorenzo
and Erik for the V6 RA kick in the pants.
9. References 9. References
9.1. Normative References 9.1. Normative References
[IANA.AS_Numbers]
IANA, "Autonomous System (AS) Numbers",
<http://www.iana.org/assignments/as-numbers>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
9.2. Informative References 9.2. Informative References
[I-D.ietf-sidr-iana-objects] [I-D.ietf-sidr-iana-objects]
Manderson, T., Vegoda, L., and S. Kent, "RPKI Objects Manderson, T., Vegoda, L., and S. Kent, "RPKI Objects
issued by IANA", draft-ietf-sidr-iana-objects-03 (work in issued by IANA", draft-ietf-sidr-iana-objects-03 (work in
progress), May 2011. progress), May 2011.
Appendix A. Changes / Author Notes. Appendix A. Changes / Author Notes.
[RFC Editor: Please remove this section before publication ] [RFC Editor: Please remove this section before publication ]
From -02 to 03:
o Removed the DHCPv6 stuff (as suggested / requested by Erik Kline)
o Simplified / cleaned up text (I'm inclined to waffle on, then trim
the fluff)
o This was written on a United flight with in-flight WiFi -
unfortnatly I couldn't use it because their CP was borked.
From -01 to 02: From -01 to 02:
o Added the IPv6 RA stuff. o Added the IPv6 RA stuff.
From -00 to -01: From -00 to -01:
o Many nits and editorial changes. o Many nits and editorial changes.
o Whole bunch of extra text and review from Wes George on v6. o Whole bunch of extra text and review from Wes George on v6.
 End of changes. 31 change blocks. 
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