draft-ietf-v6ops-ipv6-ehs-in-real-world-01.txt   draft-ietf-v6ops-ipv6-ehs-in-real-world-02.txt 
IPv6 Operations Working Group (v6ops) F. Gont IPv6 Operations Working Group (v6ops) F. Gont
Internet-Draft SI6 Networks / UTN-FRH Internet-Draft SI6 Networks / UTN-FRH
Intended status: Informational J. Linkova Intended status: Informational J. Linkova
Expires: April 17, 2016 Google Expires: June 12, 2016 Google
T. Chown T. Chown
University of Southampton University of Southampton
W. Liu W. Liu
Huawei Technologies Huawei Technologies
October 15, 2015 December 10, 2015
Observations on the Dropping of Packets with IPv6 Extension Headers in Observations on the Dropping of Packets with IPv6 Extension Headers in
the Real World the Real World
draft-ietf-v6ops-ipv6-ehs-in-real-world-01 draft-ietf-v6ops-ipv6-ehs-in-real-world-02
Abstract Abstract
This document presents real-world data regarding the extent to which This document presents real-world data regarding the extent to which
packets with IPv6 extension headers are dropped in the Internet (as packets with IPv6 extension headers are dropped in the Internet (as
measured in August 2014), and where in the network such dropping originally measured in August 2014 and later in June 2015, with
occurs. The aforementioned results serve as a problem statement that similar results), and where in the network such dropping occurs. The
is expected to trigger operational advice on the filtering of IPv6 aforementioned results serve as a problem statement that is expected
packets carrying IPv6 Extension Headers, so that the situation to trigger operational advice on the filtering of IPv6 packets
improves over time. This document also explains how the carrying IPv6 Extension Headers, so that the situation improves over
aforementioned results were obtained, such that the corresponding time. This document also explains how the aforementioned results
measurements can be reproduced by other members of the community. were obtained, such that the corresponding measurements can be
reproduced by other members of the community and repeated over time
to observe changes in the handling of packets with IPv6 extension
headers.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on April 17, 2016. This Internet-Draft will expire on June 12, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Support of IPv6 Extension Headers in the Internet . . . . . . 3 2. Support of IPv6 Extension Headers in the Internet . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 7 6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 8 6.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. Reproducing Our Experiment . . . . . . . . . . . . . 9 Appendix A. Reproducing Our Experiment . . . . . . . . . . . . . 8
A.1. Obtaining the List of Domain Names . . . . . . . . . . . 10 A.1. Obtaining the List of Domain Names . . . . . . . . . . . 8
A.2. Obtaining AAAA Resource Records . . . . . . . . . . . . . 10 A.2. Obtaining AAAA Resource Records . . . . . . . . . . . . . 9
A.3. Filtering the IPv6 Address Datasets . . . . . . . . . . . 10 A.3. Filtering the IPv6 Address Datasets . . . . . . . . . . . 9
A.4. Performing Measurements with Each IPv6 Address Dataset . 11 A.4. Performing Measurements with Each IPv6 Address Dataset . 10
A.5. Obtaining Statistics from our Measurements . . . . . . . 12 A.5. Obtaining Statistics from our Measurements . . . . . . . 11
Appendix B. Measurements Caveats . . . . . . . . . . . . . . . . 13 Appendix B. Measurements Caveats . . . . . . . . . . . . . . . . 12
B.1. Isolating the Dropping Node . . . . . . . . . . . . . . . 13 B.1. Isolating the Dropping Node . . . . . . . . . . . . . . . 12
B.2. Obtaining the Responsible Organization for the Packet B.2. Obtaining the Responsible Organization for the Packet
Drops . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Drops . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Appendix C. Troubleshooting Packet Drops due to IPv6 Extension Appendix C. Troubleshooting Packet Drops due to IPv6 Extension
Headers . . . . . . . . . . . . . . . . . . . . . . 15 Headers . . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
IPv6 Extension Headers (EHs) allow for the extension of the IPv6 IPv6 Extension Headers (EHs) allow for the extension of the IPv6
protocol, and provide support for core functionality such as IPv6 protocol, and provide support for core functionality such as IPv6
fragmentation. While packets employing IPv6 Extension Headers have fragmentation. While packets employing IPv6 Extension Headers have
been suspected to be dropped in some IPv6 deployments, there was not been suspected to be dropped in some IPv6 deployments, there was not
much concrete data on the topic. Some preliminary measurements have much concrete data on the topic. Some preliminary measurements have
been presented in [PMTUD-Blackholes], [Gont-IEPG88] and been presented in [PMTUD-Blackholes], [Gont-IEPG88] and
[Gont-Chown-IEPG89], whereas [Linkova-Gont-IEPG90] presents more [Gont-Chown-IEPG89], whereas [Linkova-Gont-IEPG90] presents more
comprehensive results on which this document is based. comprehensive results on which this document is based.
This document presents real-world data regarding the extent to which This document presents real-world data regarding the extent to which
packets containing IPv6 Extension Headers are dropped in the packets containing IPv6 Extension Headers are dropped in the
Internet, as measured in August 2014 (pending operational advice in Internet, as measured in August 2014 and later in June 2015 with
this area). The results presented in this document indicate that in similar results (pending operational advice in this area). The
the scenarios where the corresponding measurements were performed, results presented in this document indicate that in the scenarios
the use of IPv6 extension headers can lead to packet drops. We note where the corresponding measurements were performed, the use of IPv6
that, in particular, packet drops occurring at transit networks are extension headers can lead to packet drops. We note that, in
particular, packet drops occurring at transit networks are
undesirable, and it is hoped and expected that this situation will undesirable, and it is hoped and expected that this situation will
improve over time. improve over time.
2. Support of IPv6 Extension Headers in the Internet 2. Support of IPv6 Extension Headers in the Internet
This section summarizes the results obtained when measuring the This section summarizes the results obtained when measuring the
support of IPv6 Extension Headers on the path towards different types support of IPv6 Extension Headers on the path towards different types
of public IPv6 servers. Two sources of information were employed for of public IPv6 servers. Two sources of information were employed for
the list of public IPv6 servers: the "World IPv6 Launch Day" site the list of public IPv6 servers: the "World IPv6 Launch Day" site
(http://www.worldipv6launch.org/) and Alexa's top 1M web sites (http://www.worldipv6launch.org/) and Alexa's top 1M web sites
skipping to change at page 5, line 30 skipping to change at page 5, line 30
to be dropped in a different AS (lower, in parentheses) to be dropped in a different AS (lower, in parentheses)
NOTE: As an example, we note that the cell describing the support NOTE: As an example, we note that the cell describing the support
of IPv6 packets with DO8 for webservers (containing the value of IPv6 packets with DO8 for webservers (containing the value
"11.88% (17.60%/20.80%)") should be read as: "when sending IPv6 "11.88% (17.60%/20.80%)") should be read as: "when sending IPv6
packets with DO8 to public webservers, 11.88% of such packets get packets with DO8 to public webservers, 11.88% of such packets get
dropped. Among those packets that get dropped, 17.60%/20.80% dropped. Among those packets that get dropped, 17.60%/20.80%
(best case / worst case) of them get dropped at an AS other than (best case / worst case) of them get dropped at an AS other than
the destination AS". the destination AS".
+--------+------------------+-------------------+-------------------+
| EH | Webservers | Mailservers | Nameservers |
| Type | | | |
+--------+------------------+-------------------+-------------------+
| DO8 | 11.88% | 17.07% | 15.37% |
| | (17.60%/20.80%) | (6.35%/26.98%) | (14.29%/33.46%) |
+--------+------------------+-------------------+-------------------+
| HBH8 | 40.70% | 48.86% | 43.25% |
| | (31.43%/40.00%) | (40.50%/65.42%) | (42.49%/72.07%) |
+--------+------------------+-------------------+-------------------+
| FH512 | 30.51% | 39.17% | 38.55% |
| | (5.08%/6.78%) | (2.91%/12.73%) | (3.90%/13.96%) |
+--------+------------------+-------------------+-------------------+
Table 2: WIPv6LD dataset: Packet drop rate for different EH types,
and estimated percentage of dropped packets that were deemed to be
dropped in a different AS (lower, in parentheses)
NOTE: This table contains the same information as Table 1, but
makes it easier to obtain the drop rates for each EH type. Each
cell should be read in exactly the same way as each cell in
Table 1.
+-------------+-----------------+-----------------+-----------------+ +-------------+-----------------+-----------------+-----------------+
| Dataset | DO8 | HBH8 | FH512 | | Dataset | DO8 | HBH8 | FH512 |
+-------------+-----------------+-----------------+-----------------+ +-------------+-----------------+-----------------+-----------------+
| Webservers | 10.91% | 39.03% | 28.26% | | Webservers | 10.91% | 39.03% | 28.26% |
| | (46.52%/53.23%) | (36.90%/46.35%) | (53.64%/61.43%) | | | (46.52%/53.23%) | (36.90%/46.35%) | (53.64%/61.43%) |
+-------------+-----------------+-----------------+-----------------+ +-------------+-----------------+-----------------+-----------------+
| Mailservers | 11.54% | 45.45% | 35.68% | | Mailservers | 11.54% | 45.45% | 35.68% |
| | (2.41%/21.08%) | (41.27%/61.13%) | (3.15%/10.92%) | | | (2.41%/21.08%) | (41.27%/61.13%) | (3.15%/10.92%) |
+-------------+-----------------+-----------------+-----------------+ +-------------+-----------------+-----------------+-----------------+
| Nameservers | 21.33% | 54.12% | 55.23% | | Nameservers | 21.33% | 54.12% | 55.23% |
| | (10.27%/56.80%) | (50.64%/81.00%) | (5.66%/32.23%) | | | (10.27%/56.80%) | (50.64%/81.00%) | (5.66%/32.23%) |
+-------------+-----------------+-----------------+-----------------+ +-------------+-----------------+-----------------+-----------------+
Table 3: Alexa's top 1M sites dataset: Packet drop rate for different Table 2: Alexa's top 1M sites dataset: Packet drop rate for different
destination types, and estimated percentage of dropped packets that destination types, and estimated percentage of dropped packets that
were deemed to be dropped in a different AS (lower, in parentheses) were deemed to be dropped in a different AS (lower, in parentheses)
+--------+------------------+-------------------+-------------------+
| EH | Webservers | Mailservers | Nameservers |
| Type | | | |
+--------+------------------+-------------------+-------------------+
| DO8 | 10.91% | 11.54% | 21.33% |
| | (46.52%/53.23%) | (2.41%/21.08%) | (10.27%/56.80%) |
+--------+------------------+-------------------+-------------------+
| HBH8 | 39.03% | 45.45% | 54.12% |
| | (36.90%/46.35%) | (41.27%/61.13%) | (50.64%/81.00%) |
+--------+------------------+-------------------+-------------------+
| FH512 | 28.26% | 35.68% | 55.23% |
| | (53.64%/61.43%) | (3.15%/10.92%) | (5.66%/32.23%) |
+--------+------------------+-------------------+-------------------+
Table 4: Alexa's top 1M sites dataset: Packet drop rate for different
EH types, and estimated percentage of dropped packets that were
deemed to be dropped in a different AS (lower, in parentheses)
NOTE: This table contains the same information as Table 3, but
makes it easier to obtain the drop rates for each EH type. Each
cell should be read in exactly the same way as each cell in
Table 3.
There are a number of observations to be made based on the results There are a number of observations to be made based on the results
presented above. Firstly, while it has been generally assumed that presented above. Firstly, while it has been generally assumed that
it is IPv6 fragments that are dropped by operators, our results it is IPv6 fragments that are dropped by operators, our results
indicate that it is IPv6 extension headers in general that result in indicate that it is IPv6 extension headers in general that result in
packet drops. Secondly, our results indicate that a significant packet drops. Secondly, our results indicate that a significant
percentage of such packet drops occurs in transit Autonomous Systems; percentage of such packet drops occurs in transit Autonomous Systems;
that is, the packet drops are not under the control of the same that is, the packet drops are not under the control of the same
organization as the final destination. organization as the final destination.
3. IANA Considerations 3. IANA Considerations
skipping to change at page 8, line 16 skipping to change at page 7, line 20
Control Message Protocol (ICMPv6) for the Internet Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", RFC 4443, Protocol Version 6 (IPv6) Specification", RFC 4443,
DOI 10.17487/RFC4443, March 2006, DOI 10.17487/RFC4443, March 2006,
<http://www.rfc-editor.org/info/rfc4443>. <http://www.rfc-editor.org/info/rfc4443>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, DOI 10.17487/RFC4861, September 2007,
<http://www.rfc-editor.org/info/rfc4861>. <http://www.rfc-editor.org/info/rfc4861>.
[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation
Algorithm", RFC 6145, DOI 10.17487/RFC6145, April 2011,
<http://www.rfc-editor.org/info/rfc6145>.
[RFC6946] Gont, F., "Processing of IPv6 "Atomic" Fragments",
RFC 6946, DOI 10.17487/RFC6946, May 2013,
<http://www.rfc-editor.org/info/rfc6946>.
6.2. Informative References 6.2. Informative References
[blackhole6] [blackhole6]
blackhole6, , "blackhole6 tool manual page", blackhole6, , "blackhole6 tool manual page",
<http://www.si6networks.com/tools/ipv6toolkit>, 2014. <http://www.si6networks.com/tools/ipv6toolkit>, 2014.
[Gont-Chown-IEPG89] [Gont-Chown-IEPG89]
Gont, F. and T. Chown, "A Small Update on the Use of IPv6 Gont, F. and T. Chown, "A Small Update on the Use of IPv6
Extension Headers", IEPG 89. London, UK. March 2, 2014, Extension Headers", IEPG 89. London, UK. March 2, 2014,
<http://www.iepg.org/2014-03-02-ietf89/ <http://www.iepg.org/2014-03-02-ietf89/
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