Internet DRAFT - draft-yan-sidr-roa-mergence
draft-yan-sidr-roa-mergence
Secure Inter-Domain Routing Z. Yan
Internet-Draft Y. Fu
Intended status: Informational X. Liu
Expires: November 7, 2016 G. Geng
CNNIC
May 6, 2016
Problem Statement and Considerations for ROA Mergence
draft-yan-sidr-roa-mergence-00
Abstract
The address space holder needs to issue an ROA object when it
authorizes one or more ASes to originate routes to multiple prefixes.
During the process of ROA issuance, the address space holder needs to
specify an origin AS for a list of IP prefixes. Besides, the address
space holder has a free choice to put multiple prefixes into a single
ROA or issue separate ROAs for each prefix based on the current
specification. This memo analyzes and presents some operational
problems which may be caused by the misconfigurations of ROAs
containing multiple IP prefixes. Some suggestions and considerations
also have been proposed.
Status of This Memo
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Copyright Notice
Copyright (c) 2016 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Problem statement and Analysis . . . . . . . . . . . . . . . 3
3.1. Statistical analysis of ROA mergence . . . . . . . . . . 3
3.2. Experimental analysis of ROA mergence . . . . . . . . . . 5
3.3. Problem statement . . . . . . . . . . . . . . . . . . . . 8
4. Suggestions and Considerations . . . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
Route Origin Authorization (ROA) is a digitally signed object which
is used to identify that a single AS has been authorized by the
address space holder to originate routes to one or more prefixes
within the address space[RFC6482].If the address space holder needs
to authorize more than one ASes to advertise the same set of address
prefixes, the holder must issue multiple ROAs, one per AS number.
However, at present there are no mandatory requirements in any RFCs
describing that the address space holders must issue a separate ROA
for each prefix or a ROA for multiple prefixes.
Each ROA contains an "asID" field and an "ipAddrBlocks" field. The
"asID" field contains one single AS number which is authorized to
originate routes to the given IP address prefixes. The
"ipAddrBlocks" field contains one or more IP address prefixes to
which the AS is authorized to originate the routes. The ROA mergence
is a common case that each ROA contains exactly one AS number but may
contain multiple IP address prefixes in the operational process of
ROA issuance.
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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].
3. Problem statement and Analysis
3.1. Statistical analysis of ROA mergence
As mentioned above, the address space holder needs to issue an ROA
object when it authorizes one or more ASes to originate routes to
multiple prefixes. During the process of ROA issuance, the address
space holder needs to specify an origin AS for a list of IP prefixes.
Besides, the address space holder has a free choice to put multiple
prefixes into a single ROA or issue separate ROAs for each prefix
based on the current specification.
On our RPKI testbed, the Trust Anchor Locator (TAL) files configured
by RP correspond to the five RIRs' RPKI Trust Anchors. By using
these TAL files, all the ROA objects issued in each region (the five
RIRs) around the world are collected and validated with the RPKI
Relying Party tools provided by rpki.net. According to the analysis
on these data, some statistical results are described in Table. 1.
+----------------+------------------------+-------------------------+
| The total | The number of ROAs | The number of ROAs with |
| number of ROAs | with a single prefix | multiple prefixes |
+----------------+------------------------+-------------------------+
| 5027 | 2341 | 2686 |
+----------------+------------------------+-------------------------+
Table.1 Statistical results of all ROAs
As shown in Table. 1, by now (as of April 19, 2016), the total number
of ROA objects issued around the world is about 5027. The result is
in accordance with the statistics provided by RIPE NCC and Internet
Multifeed Co. (MF). Based on the further analysis on these ROA
objects, it is found that: the number of ROAs containing only one
prefix is about 2341 (account for 46.6% of all ROA objects), and the
number of ROAs containing two or more prefixes is about 2686 (account
for 53.4% of all ROA objects).
In the 2686 ROA objects which each one contains two or more prefixes,
the number of IP address prefixes are calculated and analyzed. The
statistical results are shown in Table. 2.
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+------------------+---------------+--------------------------------+
| The number of | The number of | The average number of prefixes |
| prefixes | ROAs | in each ROA |
+------------------+---------------+--------------------------------+
| 20379 | 2686 | 7.59 |
+------------------+---------------+--------------------------------+
Table. 2 Statistical results of the 2686 ROAs
As described in Table. 2, there are 20379 IP address prefixes in the
2686 ROA objects. And the average number of prefixes in each ROA is
7.59 (20379/2686). In addition, four types of ROAs are analyzed and
calculated in the 2686 ROAs: ROAs each contains
2-10/11-50/51-100/>100 IP address prefixes. The statistical results
are presented in Table. 3.
+----------+----------+-----------+-----------+-----------+---------+
| ROA | ROA with | ROA with | ROA with | ROA with | Total |
| types | 2-10 | 11-50 | 51-100 | >100 | |
| | prefixes | prefixes | prefixes | prefixes | |
+----------+----------+-----------+-----------+-----------+---------+
| The | 2316 | 325 | 29 | 16 | 2686 |
| number | | | | | |
| of ROAs | | | | | |
| The | 86.22% | 12.10% | 1.08% | 0.60% | 100.00% |
| ratio of | | | | | |
| ROAs | | | | | |
| The | 8849 | 6563 | 1917 | 3050 | 20379 |
| number | | | | | |
| of | | | | | |
| prefixes | | | | | |
| The | 43.42% | 32.20% | 9.41% | 14.97% | 100.00% |
| ratio of | | | | | |
| prefixes | | | | | |
+----------+----------+-----------+-----------+-----------+---------+
Table. 3 Statistical results of four types of ROAs
As shown in Table. 3, taking the first type of ROA as an example,
there are 2316 ROAs (account for 86.22% of the 2628 ROA objects)
which each contains 2-10 IP address prefixes, and the total number of
IP prefixes in these 2316 ROAs is 8849 (account for 43.42% of the
20379 prefixes).
According to the third row (the ratio of ROAs) in Table. 3, it shows
the trend that the address space holders tend to issue each ROA
object with fewer IP prefixes (more than 98% of ROAs containing less
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than 50 prefixes), but they still tend to put multiple prefixes into
one single ROA.
It should also be paid more attention that among all the ROAs issued
today, a single ROA may contain a large number of IP address
prefixes. In the statistical results, it is found that there exists
two ROAs (corresponding to ASN 3215 and ASN 9299) which each contains
more than 300 IP address prefixes (324 and 375 respectively).
3.2. Experimental analysis of ROA mergence
A large number of experiments for the process of ROA issuance have
been made on our RPKI testbed, it is found that the misconfigurations
during the issuance may cause the ROAs which have been issued to be
revoked. The corresponding scenarios are as follows.
AS shown in Fig. 1, an ISP needed to issue two ROA objects
respectively to authorize ASN 64500 to originate routes to IP
prefixes 192.0.2.128/28 and ASN 64501 to originate routes to IP
prefixes 198.51.100.128/28. The operations are simulated on our RPKI
testbed.
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+-----------+
| | ASNs:
| IANA |----- 0-4294967295
| | IP Prefixes:
| | 0.0.0.0/0
+-----|-----+
| ASNs:
+-----|-----+ 64497-64510
| | 65537-65550
| | IP Prefixes
| APNIC ------ 192.0.2.118/25
| | 198.51.100.128/25
| | 203.0.113.128/25
+-----|-----+
|
+-----|-----+ ASNs:
| | 64498-64505
| | IP Prefixes
| | 192.0.2.128/26
| CNNIC ------ 198.51.100.128/26
| | 203.0.113.128/26
+-----|-----+
|
+-----|-----+
| | ASNs:
| | 64500-64505
| | IP Prefixes:
| ISP ------ 192.0.2.128/27
| | 198.51.100.128/27
| | 203.0.113.128/27
+-----+-----+
| --------------
| //// \\\\
| // ROA1: \\
---------------| 64500->192.0.2.128/28 |
| ROA2: |
| 64501->198.51.100.128/28 |
\\ //
\\\\ ////
--------------
Fig. 1 Scenario of ROA issuance
The ROA objects issued by ISP could be checked with the
"show_published_objects" command. And as shown in Fig. 2, ISP has
issued two ROA objects M74Rq1am9m4YUairntkXTRAx6Wg.roa and
vulw_jMZBy7-ktn7nyhlpchBKZY.roa to respectively authorize ASN 64500
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to originate routes to IP prefixes 192.0.2.128/28 and ASN 64501 to
originate routes to IP prefixes 198.51.100.128/28.
test@~$cat ISPROA.csv
192.0.2.128/28 64500 Group1
198.51.100.128/28 64501 Group2
test@~$ rpkic -i ISP load_roa_requests ISPROA.csv
test@~$ rpkic -i ISP show_published_objects
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.crl
2016-04-19T10:34:04Z 594CB167AF4E81424EBEA7C1A5FD8DDE216D5C69
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.mft
2016-04-19T10:34:04Z 17C98CBFB179D60D9D0A6D52C2629B7A8DEA8A9C
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/M74Rq1am9m4YUairntkXTRAx6Wg.roa
2016-04-19T09:20:20Z 0CFD927D1522BF43FC52B748F274646387569222
64500 192.0.2.128/28
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/vulw_jMZBY7-KTN7nyhlpchBKZY.roa
2016-04-19T10:34:04Z 305866D0c4ee5e156ebeda811d3540bf0e094043
64501 198.51.100.128/28
Fig. 2 Check the ROAs issued by ISP
Afterwards, ISP wanted to authorize ASN 64501 to originate routes to
another IP prefixes 203.0.113.128/28, so it modified the ISPROA.csv
file and operated the "load_roa_requests" command again.
test@~$cat ISPROA.csv
192.0.2.128/28 64500 Group1
198.51.100.128/28 64501 Group2
203.0.113.128/28 64501 Group2
test@~$ rpkic -i ISP load_roa_requests ISPROA.csv
test@~$ rpkic -i ISP show_published_objects
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.crl
2016-04-19T10:38:03Z 2606EAA75AB60BE7785AE0CB0599D984AFD5BDB5
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.mft
2016-04-19T10:38:03Z 10F3F9249F0A6A636BF8143075693681B45A4BC2
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/M74Rq1am9m4YUairntkXTRAx6Wg.roa
2016-04-19T09:20:20Z 0CFD927D1522BF43FC52B748F274646387569222
64500 192.0.2.128/28
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/vO3whtjMpYxxyva4BxRqI2H8eqA.roa
2016-04-19T10:38:03Z 4B85FDBABEC567A9DD8DA5745B34A201390F4530
64501 198.51.100.128/28,203.0.113.128/28
Fig. 3 Add a new authorization
As shown in Fig. 3, after processing the above operations, a new ROA
object vO3WhtjMpYxxyva4BxRqI2H8eqA.roa which contained two IP
prefixes was issued. One thing which needs to be noticed is that in
the ISPROA.csv file the third column of the last two lines (with
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respect to ASN 64501) are set as the same label "Group2" to make sure
that the authorizations to the two IP prefixes will be issued into a
single ROA.
Now, ISP wants to authorize ASN 64500 to originate routes to IP
prefixes 203.0.113.128/28 as well, but when it modifies the
ISPROA.csv file, it appends 204.0.113.128/28 (or any prefixes that do
not belong to ISP) instead of 203.0.113.128/28 into the ISPROA.csv
file by mistake. And then, when it operates the "load_roa_requests"
command, something unexpected will happen.
test@~$cat ISPROA.csv
192.0.2.128/28 64500 Group1
204.0.113.128/28 64500 Group1
198.51.100.128/28 64501 Group2
203.0.113.128/28 64501 Group2
test@~$ rpkic -i ISP load_roa_requests ISPROA.csv
test@~$ rpkic -i ISP show_published_objects
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.crl
2016-04-19T12:39:47Z 2DD037213237D72AF6CE95F8F37D1F08E8B49A37
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/duPylfF7Hv31rpOa4dVVCZnRkmk.mft
2016-04-19T12:39:47Z 735D9723B8C6D8214DA78117D27E529AA47E14B6
rsync://ubuntu/rpki/IANA/APNIC/CNNIC/ISP/vO3whtjMpYxxyva4BxRqI2H8eqA.roa
2016-04-19T10:38:03Z 4B85FDBABEC567A9DD8DA5745B34A201390F4530
64501 198.51.100.128/28,203.0.113.128/28
Fig. 4 Add an incorrect authorization by mistake
As shown in Fig. 4, a legitimate ROA object was revoked because of
ISP's misconfiguration. Obviously, this misconfiguration may lead to
some serious consequences to RPKI (such as legitimate BGP routes are
misclassified as "invalid").
3.3. Problem statement
It concludes that the misconfigurations of ROAs containing multiple
IP address prefixes may lead to much more serious consequences than
ROAs with fewer IP address prefixes. According to the above
statistical and experimental analysis, misconfigurations of the ROAs
which contain more than 300 IP address prefixes may cause a large-
scale network interruption.
Another potential influence of misconfigurations of ROAs containing
multiple IP prefixes on BGP routers may be considered. For the ROA
containing multiple prefixes, once increase or delete one <AS,
ip_prefix> pair in it, this ROA will be reissued. Through
sychronization with repository, RPs fetch a new ROA object and then
notify and send all the <AS, ip_prefix> pairs in this ROA to BGP
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routers. That is to say, the update of the ROA containing multiple
IP address prefixes will lead to redundant transmission between RP
and BGP routers . So frequent update of these ROAs will increase the
convergency time of BGP routers and reduce their performance
obviously.
4. Suggestions and Considerations
Based on the statistical and experimental analysis, following
considerations should be considered during the process of ROA
issuance:
1) The issuance of ROAs containing a large number of IP prefixes may
lead to misconfigurations more easily than ROAs with fewer IP
prefixes.
A ROA which contains a large number of IP prefixes is more vulnerable
to misconfigurations, because any misconfiguration of these prefixes
may cause the legitimate ROA to be revoked. Besides, since the
misconfigurations of ROAs containing a larger number of IP address
prefixes may lead to much more serious consequences (a large-scale
network interruption) than ROAs with fewer IP address prefixes, it is
suggested to avoid issuing ROAs with a large number of IP address
prefixes.
2) The number of ROAs containing multiple IP prefixes should be
limited and the number of IP prefixes in each ROA should also be
limited.
The extreme case (a single ROA can only contain one IP address
prefix) may lead to too much ROA objects globally, which may in turn
become a burden for RPs to synchronize and validate all these ROA
objects with the fully deployment of RPKI. So a tradeoff between the
number of ROAs and the number of IP prefixes in a single ROA should
be considered.
3) A safeguard scheme is essential to protect the process of ROA
issuance
Considering the misconfigurations during the process of ROA issuance
are inevitable and the serious consequences they may lead to, a
safeguard scheme to protect and monitor the process of ROA issuance
should be considered.
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5. Security Considerations
TBD.
6. IANA Considerations
This draft does not request any IANA action.
7. Acknowledgements
The authors would like to thanks the valuable comments made by XXX
and other members of sidr WG.
This document was produced using the xml2rfc tool [RFC2629].
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support
Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
February 2012, <http://www.rfc-editor.org/info/rfc6480>.
[RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
Origin Authorizations (ROAs)", RFC 6482,
DOI 10.17487/RFC6482, February 2012,
<http://www.rfc-editor.org/info/rfc6482>.
[RFC6486] Austein, R., Huston, G., Kent, S., and M. Lepinski,
"Manifests for the Resource Public Key Infrastructure
(RPKI)", RFC 6486, DOI 10.17487/RFC6486, February 2012,
<http://www.rfc-editor.org/info/rfc6486>.
8.2. Informative References
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
DOI 10.17487/RFC2629, June 1999,
<http://www.rfc-editor.org/info/rfc2629>.
[RFC5914] Housley, R., Ashmore, S., and C. Wallace, "Trust Anchor
Format", RFC 5914, DOI 10.17487/RFC5914, June 2010,
<http://www.rfc-editor.org/info/rfc5914>.
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Authors' Addresses
Zhiwei Yan
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
P.R. China
Email: yanzhiwei@cnnic.cn
Yu Fu
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
P.R. China
Email: fuyu@cnnic.cn
Xiaowei Liu
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
P.R. China
Email: liuxiaowei@cnnic.cn
Guanggang Geng
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
P.R. China
Email: gengguanggang@cnnic.cn
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