draft-ietf-dnsop-respsize-03.txt   draft-ietf-dnsop-respsize-04.txt 
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Copyright (C) The Internet Society (2006). All Rights Reserved. Copyright (C) The Internet Society (2006). All Rights Reserved.
Abstract Abstract
With a mandated default minimum maximum message size of 512 octets, With a mandated default minimum maximum message size of 512 octets,
the DNS protocol presents some special problems for zones wishing to the DNS protocol presents some special problems for zones wishing to
expose a moderate or high number of authority servers (NS RRs). This expose a moderate or high number of authority servers (NS RRs). This
document explains the operational issues caused by, or related to document explains the operational issues caused by, or related to
this response size limit. this response size limit.
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1 - Introduction and Overview 1 - Introduction and Overview
1.1. The DNS standard (see [RFC1035 4.2.1]) limits message size to 512 1.1. The DNS standard (see [RFC1035 4.2.1]) limits message size to 512
octets. Even though this limitation was due to the required minimum UDP octets. Even though this limitation was due to the required minimum IP
reassembly limit for IPv4, it is a hard DNS protocol limit and is not reassembly limit for IPv4, it became a hard DNS protocol limit and is
implicitly relaxed by changes in transport, for example to IPv6. not implicitly relaxed by changes in transport, for example to IPv6.
1.2. The EDNS0 protocol extension (see [RFC2671 2.3, 4.5]) permits 1.2. The EDNS0 protocol extension (see [RFC2671 2.3, 4.5]) permits
larger responses by mutual agreement of the requestor and responder. larger responses by mutual agreement of the requestor and responder.
However, deployment of EDNS0 cannot be expected to reach every Internet However, deployment of EDNS0 cannot be expected to reach every Internet
resolver in the short or medium term. The 512 octet message size limit resolver in the short or medium term. The 512 octet message size limit
remains in practical effect at this time. remains in practical effect at this time.
1.3. Since DNS responses include a copy of the request, the space 1.3. Since DNS responses include a copy of the request, the space
available for response data is somewhat less than the full 512 octets. available for response data is somewhat less than the full 512 octets.
Negative responses are quite small, but for positive and delegation Negative responses are quite small, but for positive and delegation
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2.1. A delegation response will include the following elements: 2.1. A delegation response will include the following elements:
Header Section: fixed length (12 octets) Header Section: fixed length (12 octets)
Question Section: original query (name, class, type) Question Section: original query (name, class, type)
Answer Section: (empty) Answer Section: (empty)
Authority Section: NS RRset (nameserver names) Authority Section: NS RRset (nameserver names)
Additional Section: A and AAAA RRsets (nameserver addresses) Additional Section: A and AAAA RRsets (nameserver addresses)
2.2. If the total response size would exceed 512 octets, and if the data 2.2. If the total response size would exceed 512 octets, and if the data
that would not fit belonged in the answer or authority section, then the that would not fit was "required", then the TC bit will be set
TC bit will be set (indicating truncation) which may cause the requestor (indicating truncation). This will usually cause the requestor to retry
to retry using TCP, depending on what information was desired and what using TCP, depending on what information was desired and what
information was omitted. If a retry using TCP is needed, the total cost information was omitted. (For example, truncation in the authority
of the transaction is much higher. (See [RFC1123 6.1.3.2] for details section is of no interest to a stub resolver who only plans to consume
on the requirement that UDP be attempted before falling back to TCP.) the answer section.) If a retry using TCP is needed, the total cost of
the transaction is much higher. See [RFC1123 6.1.3.2] for details on
the requirement that UDP be attempted before falling back to TCP.
2.3. RRsets are never sent partially unless TC bit set to indicate 2.3. RRsets are never sent partially unless TC bit set to indicate
truncation. When TC bit is set, the final apparent RRset in the final truncation. When TC bit is set, the final apparent RRset in the final
nonempty section must be considered "possibly damaged" (see [RFC2181 nonempty section must be considered "possibly damaged" (see [RFC1035
9]). With or without truncation, the glue present in the additional 6.2], [RFC2181 9]).
data section should be considered "possibly incomplete", and requestors
should be prepared to re-query for any damaged or missing RRsets. For
multi-transport name or mail services, this can mean querying for an
IPv6 (AAAA) RRset even when an IPv4 (A) RRset is present.
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2.4. DNS label compression allows a domain name to be instantiated only 2.4. With or without truncation, the glue present in the additional data
section should be considered "possibly incomplete", and requestors
should be prepared to re-query for any damaged or missing RRsets. Note
that truncation of the additional data section might not be signalled
via the TC bit since additional data is often optional.
2.5. DNS label compression allows a domain name to be instantiated only
once per DNS message, and then referenced with a two-octet "pointer" once per DNS message, and then referenced with a two-octet "pointer"
from other locations in that same DNS message. If all nameserver names from other locations in that same DNS message. If all nameserver names
in a message are similar (for example, all ending in ".ROOT- in a message are similar (for example, all ending in ".ROOT-
SERVERS.NET"), then more space will be available for uncompressable data SERVERS.NET"), then more space will be available for uncompressable data
(such as nameserver addresses). (such as nameserver addresses).
2.5. The query name can be as long as 255 characters of presentation 2.6. The query name can be as long as 255 characters of presentation
data, which can be up to 256 octets of network data. In this worst case data, which can be up to 256 octets of network data. In this worst case
scenario, the question section will be 260 octets in size, which would scenario, the question section will be 260 octets in size, which would
leave only 240 octets for the authority and additional sections (after leave only 240 octets for the authority and additional sections (after
deducting 12 octets for the fixed length header.) deducting 12 octets for the fixed length header.)
2.6. Average and maximum question section sizes can be predicted by the 2.7. Average and maximum question section sizes can be predicted by the
zone owner, since they will know what names actually exist, and can zone owner, since they will know what names actually exist, and can
measure which ones are queried for most often. For cost and performance measure which ones are queried for most often. For cost and performance
reasons, the majority of requests should be satisfied without truncation reasons, the majority of requests should be satisfied without truncation
or TCP retry. Some queries to non-existing names can be large, however, or TCP retry.
this is not a problem because the responses include a SOA record in the
authority section.
2.7. Requestors who deliberately send large queries to force truncation 2.8. Some queries to non-existing names can be large, but this is not a
are only increasing their own costs, and cannot effectively attack the problem because negative responses need not contain any answer,
resources of an authority server since the requestor would have to retry authority or additional records. (See [RFC2308 2.1] for more
using TCP to complete the attack. An attack that always used TCP would information about the format of negative responses.)
have a lower cost.
2.8. The minimum useful number of address records is two, since giving 2.9. The minimum useful number of name servers is two, for redundancy
only one address undermines the redundancy requirement. Implicit (see [RFC1034 4.1]). In case of multihomed name servers, it is
truncation (truncation without setting TC bit) which occurs after two advantageous to include an address record from each of several name
address records have been added to the additional data section is servers before including several address records for any one name
therefore less operationally significant than truncation which occurs server. If address records for more than one transport (for example, A
earlier. and AAAA) are available, then it is advantageous to include records of
both types early on, before the message is full.
2.9. The best case is no truncation at all. This is because many 2.10. The best case is no truncation at all. This is because many
requestors will retry using TCP by reflex, or will automatically re- requestors will retry using TCP by reflex, or will automatically re-
query for RRsets that are "possibly truncated", without considering query for RRsets that are "possibly truncated", without considering
whether the omitted data was actually necessary. whether the omitted data was actually necessary.
2.10. Each added NS RR for a zone will add a minimum of between 16 and 2.11. Each added NS RR for a zone will add a minimum of between 16 and
44 octets to every untruncated referral or negative response from the 44 octets to every untruncated referral or negative response from the
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zone's authority servers (16 octets for an NS RR, 16 octets for an A RR, zone's authority servers (16 octets for an NS RR, 16 octets for an A RR,
and 28 octets for an AAAA RR), in addition to whatever space is taken by and 28 octets for an AAAA RR), in addition to whatever space is taken by
the nameserver name (NS NSDNAME as well as A or AAAA owner name). the nameserver name (NS NSDNAME as well as A or AAAA owner name).
INTERNET-DRAFT June 2006 RESPSIZE 2.12. While DNS distinguishes between necessary and optional resource
records, this distinction is according to protocol elements necessary to
signify facts, and takes no official notice of protocol content
necessary to ensure correct operation. For example, a nameserver name
that is in or below the zone cut being described by a delegation is
"necessary content," since there is no way to reach that zone unless the
parent zone's delegation includes "glue records" describing that name
server's addresses.
2.13. It is also necessary to distinguish between "explicit truncation"
where a message could not contain enough records to convey its intended
meaning, and so the TC bit has been set, and "silent truncation", where
the message was not large enough to contain some records which were "not
required", and so the TC bit was not set.
2.14. An delegation response should prioritize glue records as follows.
first
All glue RRsets for one name server whose name is in or below the
zone being delegated, or which has multiple address RRsets (currently
A and AAAA), or preferrably both;
second
Alternate between adding all glue RRsets for any name servers whose
names are in or below the zone being delegated, and all glue RRsets
for any name servers who have multiple address RRsets (currently A
and AAAA);
thence
All other glue RRsets, in any order.
The goal of this priority scheme is to offer "necessary" glue first,
avoiding silent truncation for this glue if possible.
2.15. If any "necessary content" is silently truncated, then it is
advisable that the TC bit be set in order to force a TCP retry, rather
than have the zone be unreachable. Note that a parent server's proper
response to a query for in-child glue or below-child glue is a referral
rather than an answer, and that this referral MUST be able to contain
the in-child or below-child glue, and that in outlying cases, only EDNS
or TCP will be large enough to contain that data.
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3 - Analysis 3 - Analysis
3.1. An instrumented protocol trace of a best case delegation response 3.1. An instrumented protocol trace of a best case delegation response
follows. Note that 13 servers are named, and 13 addresses are given. follows. Note that 13 servers are named, and 13 addresses are given.
This query was artificially designed to exactly reach the 512 octet This query was artificially designed to exactly reach the 512 octet
limit. limit.
;; flags: qr rd; QUERY: 1, ANS: 0, AUTH: 13, ADDIT: 13 ;; flags: qr rd; QUERY: 1, ANS: 0, AUTH: 13, ADDIT: 13
;; QUERY SECTION: ;; QUERY SECTION:
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F.GTLD-SERVERS.NET. 86400 A 192.35.51.30 ;; @400 F.GTLD-SERVERS.NET. 86400 A 192.35.51.30 ;; @400
G.GTLD-SERVERS.NET. 86400 A 192.42.93.30 ;; @416 G.GTLD-SERVERS.NET. 86400 A 192.42.93.30 ;; @416
H.GTLD-SERVERS.NET. 86400 A 192.54.112.30 ;; @432 H.GTLD-SERVERS.NET. 86400 A 192.54.112.30 ;; @432
I.GTLD-SERVERS.NET. 86400 A 192.43.172.30 ;; @448 I.GTLD-SERVERS.NET. 86400 A 192.43.172.30 ;; @448
J.GTLD-SERVERS.NET. 86400 A 192.48.79.30 ;; @464 J.GTLD-SERVERS.NET. 86400 A 192.48.79.30 ;; @464
K.GTLD-SERVERS.NET. 86400 A 192.52.178.30 ;; @480 K.GTLD-SERVERS.NET. 86400 A 192.52.178.30 ;; @480
L.GTLD-SERVERS.NET. 86400 A 192.41.162.30 ;; @496 L.GTLD-SERVERS.NET. 86400 A 192.41.162.30 ;; @496
M.GTLD-SERVERS.NET. 86400 A 192.55.83.30 ;; @512 M.GTLD-SERVERS.NET. 86400 A 192.55.83.30 ;; @512
;; MSG SIZE sent: 80 rcvd: 512 ;; MSG SIZE sent: 80 rcvd: 512
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3.2. For longer query names, the number of address records supplied will 3.2. For longer query names, the number of address records supplied will
be lower. Furthermore, it is only by using a common parent name (which be lower. Furthermore, it is only by using a common parent name (which
is GTLD-SERVERS.NET in this example) that all 13 addresses are able to is GTLD-SERVERS.NET in this example) that all 13 addresses are able to
fit. The following output from a response simulator demonstrates these fit. The following output from a response simulator demonstrates these
properties: properties:
% perl respsize.pl a.dns.br b.dns.br c.dns.br d.dns.br % perl respsize.pl a.dns.br b.dns.br c.dns.br d.dns.br
a.dns.br requires 10 bytes a.dns.br requires 10 bytes
b.dns.br requires 4 bytes b.dns.br requires 4 bytes
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(Note: The response simulator program is shown in Section 5.) (Note: The response simulator program is shown in Section 5.)
Here we use the term "green" if all address records could fit, or Here we use the term "green" if all address records could fit, or
"yellow" if two or more could fit, or "orange" if only one could fit, or "yellow" if two or more could fit, or "orange" if only one could fit, or
"red" if no address record could fit. It's clear that without a common "red" if no address record could fit. It's clear that without a common
parent for nameserver names, much space would be lost. For these parent for nameserver names, much space would be lost. For these
examples we use an average/common name size of 15 octets, befitting our examples we use an average/common name size of 15 octets, befitting our
assumption of GTLD-SERVERS.NET as our common parent name. assumption of GTLD-SERVERS.NET as our common parent name.
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We're assuming an average query name size of 64 since that is the We're assuming an average query name size of 64 since that is the
typical average maximum size seen in trace data at the time of this typical average maximum size seen in trace data at the time of this
writing. If Internationalized Domain Name (IDN) or any other technology writing. If Internationalized Domain Name (IDN) or any other technology
which results in larger query names be deployed significantly in advance which results in larger query names be deployed significantly in advance
of EDNS, then new measurements and new estimates will have to be made. of EDNS, then new measurements and new estimates will have to be made.
4 - Conclusions 4 - Conclusions
4.1. The current practice of giving all nameserver names a common parent 4.1. The current practice of giving all nameserver names a common parent
(such as GTLD-SERVERS.NET or ROOT-SERVERS.NET) saves space in DNS (such as GTLD-SERVERS.NET or ROOT-SERVERS.NET) saves space in DNS
responses and allows for more nameservers to be enumerated than would responses and allows for more nameservers to be enumerated than would
otherwise be possible, since the common parent domain name only appears otherwise be possible, since the common parent domain name only appears
once in a DNS message and is referred to via "compression pointers" once in a DNS message and is referred to via "compression pointers"
thereafter. thereafter.
4.2. Thirteen (13) seems to be the effective maximum number of 4.2. If all nameserver names for a zone share a common parent, then it
is operationally advisable to make all servers for the zone so served
also be authoritative for the zone of that common parent. For example,
the root name servers (?.ROOT-SERVERS.NET) can answer authoritatively
for the ROOT-SERVERS.NET. This is to ensure that the zone's servers
always have the zone's nameservers' glue available when delegating.
4.3. Thirteen (13) seems to be the effective maximum number of
nameserver names usable traditional (non-extended) DNS, assuming a nameserver names usable traditional (non-extended) DNS, assuming a
common parent domain name, and given that response truncation is common parent domain name, and given that response truncation is
undesirable as an average case, and assuming mostly IPv4-only undesirable as an average case, and assuming mostly IPv4-only
reachability (only A RRs exist, not AAAA RRs). reachability (only A RRs exist, not AAAA RRs).
4.3. Adding two to five IPv6 nameserver address records (AAAA RRs) to a XXX 4.4. Adding up to five IPv6 nameserver address records (AAAA RRs) to
prototypical delegation that currently contains thirteen (13) IPv4 a prototypical delegation that currently contains thirteen (13) IPv4
nameserver addresses (A RRs) for thirteen (13) nameserver names under a nameserver addresses (A RRs) for thirteen (13) nameserver names under a
common parent, would not have a significant negative operational impact common parent, would not have a significant negative operational impact
on the domain name system. on the domain name system.
5 - Source Code 5 - Source Code
#!/usr/bin/perl #!/usr/bin/perl
# #
# SYNOPSIS # SYNOPSIS
# repsize.pl [ -z zone ] fqdn_ns1 fqdn_ns2 ... # repsize.pl [ -z zone ] fqdn_ns1 fqdn_ns2 ...
# if all queries are assumed to have a same zone suffix, # if all queries are assumed to have a same zone suffix,
# such as "jp" in JP TLD servers, specify it in -z option # such as "jp" in JP TLD servers, specify it in -z option
# #
use strict; use strict;
use Getopt::Std; use Getopt::Std;
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my ($sz_msg) = (512); my ($sz_msg) = (512);
my ($sz_header, $sz_ptr, $sz_rr_a, $sz_rr_aaaa) = (12, 2, 16, 28); my ($sz_header, $sz_ptr, $sz_rr_a, $sz_rr_aaaa) = (12, 2, 16, 28);
my ($sz_type, $sz_class, $sz_ttl, $sz_rdlen) = (2, 2, 4, 2); my ($sz_type, $sz_class, $sz_ttl, $sz_rdlen) = (2, 2, 4, 2);
my (%namedb, $name, $nssect, %opts, $optz); my (%namedb, $name, $nssect, %opts, $optz);
my $n_ns = 0; my $n_ns = 0;
getopt('z', %opts); getopt('z', %opts);
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if (defined($opts{'z'})) { if (defined($opts{'z'})) {
server_name_len($opts{'z'}); # just register it server_name_len($opts{'z'}); # just register it
} }
foreach $name (@ARGV) { foreach $name (@ARGV) {
my $len; my $len;
$n_ns++; $n_ns++;
$len = server_name_len($name); $len = server_name_len($name);
print "$name requires $len bytes\n"; print "$name requires $len bytes\n";
$nssect += $sz_ptr + $sz_type + $sz_class + $sz_ttl + $sz_rdlen + $len; $nssect += $sz_ptr + $sz_type + $sz_class + $sz_ttl
+ $sz_rdlen + $len;
} }
print "# of NS: $n_ns\n"; print "# of NS: $n_ns\n";
arsect(255, $nssect, $n_ns, "maximum"); arsect(255, $nssect, $n_ns, "maximum");
arsect(64, $nssect, $n_ns, "average"); arsect(64, $nssect, $n_ns, "average");
sub server_name_len { sub server_name_len {
my ($name) = @_; my ($name) = @_;
my (@labels, $len, $n, $suffix); my (@labels, $len, $n, $suffix);
$name =~ tr/A-Z/a-z/; $name =~ tr/A-Z/a-z/;
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} }
return $len; return $len;
} }
sub arsect { sub arsect {
my ($sz_query, $nssect, $n_ns, $cond) = @_; my ($sz_query, $nssect, $n_ns, $cond) = @_;
my ($space, $n_a, $n_a_aaaa, $n_p_aaaa, $ansect); my ($space, $n_a, $n_a_aaaa, $n_p_aaaa, $ansect);
$ansect = $sz_query + 1 + $sz_type + $sz_class; $ansect = $sz_query + 1 + $sz_type + $sz_class;
$space = $sz_msg - $sz_header - $ansect - $nssect; $space = $sz_msg - $sz_header - $ansect - $nssect;
$n_a = atmost(int($space / $sz_rr_a), $n_ns); $n_a = atmost(int($space / $sz_rr_a), $n_ns);
$n_a_aaaa = atmost(int($space / ($sz_rr_a + $sz_rr_aaaa)), $n_ns); INTERNET-DRAFT July 2006 RESPSIZE
$n_p_aaaa = atmost(int(($space - $sz_rr_a * $n_ns) / $sz_rr_aaaa), $n_ns);
$n_a_aaaa = atmost(int($space
/ ($sz_rr_a + $sz_rr_aaaa)), $n_ns);
$n_p_aaaa = atmost(int(($space - $sz_rr_a * $n_ns)
/ $sz_rr_aaaa), $n_ns);
printf "For %s size query (%d byte):\n", $cond, $sz_query; printf "For %s size query (%d byte):\n", $cond, $sz_query;
printf " only A is considered: "; printf " only A is considered: ";
printf "# of A is %d (%s)\n", $n_a, &judge($n_a, $n_ns); printf "# of A is %d (%s)\n", $n_a, &judge($n_a, $n_ns);
printf " A and AAAA are considered: "; printf " A and AAAA are considered: ";
printf "# of A+AAAA is %d (%s)\n", $n_a_aaaa, &judge($n_a_aaaa, $n_ns); printf "# of A+AAAA is %d (%s)\n",
$n_a_aaaa, &judge($n_a_aaaa, $n_ns);
printf " preferred-glue A is assumed: "; printf " preferred-glue A is assumed: ";
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printf "# of A is %d, # of AAAA is %d (%s)\n", printf "# of A is %d, # of AAAA is %d (%s)\n",
$n_a, $n_p_aaaa, &judge($n_p_aaaa, $n_ns); $n_a, $n_p_aaaa, &judge($n_p_aaaa, $n_ns);
} }
sub judge { sub judge {
my ($n, $n_ns) = @_; my ($n, $n_ns) = @_;
return "green" if ($n >= $n_ns); return "green" if ($n >= $n_ns);
return "yellow" if ($n >= 2); return "yellow" if ($n >= 2);
return "orange" if ($n == 1); return "orange" if ($n == 1);
return "red"; return "red";
} }
sub atmost { sub atmost {
my ($a, $b) = @_; my ($a, $b) = @_;
return 0 if ($a < 0); return 0 if ($a < 0);
return $b if ($a > $b); return $b if ($a > $b);
return $a; return $a;
} }
Security Considerations 6 - Security Considerations
The recommendations contained in this document have no known security The recommendations contained in this document have no known security
implications. implications.
IANA Considerations 7 - IANA Considerations
This document does not call for changes or additions to any IANA This document does not call for changes or additions to any IANA
registry. registry.
Acknowledgement The authors thank Peter Koch and Rob Austein for their 8 - Acknowledgement The authors thank Peter Koch and Rob Austein for
valuable comments and suggestions. their valuable comments and suggestions.
Refrenaces INTERNET-DRAFT July 2006 RESPSIZE
[RFC1035] Mockapetris, P.V., "Domain names - implementation and 9 - Refrenaces
specification", RFC1035, November 1987.
[RFC1034] Mockapetris, P.V., "Domain names - Concepts and Facilities",
RFC1034, November 1987.
[RFC1035] Mockapetris, P.V., "Domain names - Implementation and
Specification", RFC1035, November 1987.
[RFC1123] Braden, R., Ed., "Requirements for Internet Hosts - [RFC1123] Braden, R., Ed., "Requirements for Internet Hosts -
Application and Support", RFC1123, October 1989. Application and Support", RFC1123, October 1989.
[RFC2308] Andrews, M., "Negative Caching of DNS Queries (DNS NCACHE)",
RFC2308, March 1998.
[RFC2181] Elz, R., Bush, R., "Clarifications to the DNS Specification", [RFC2181] Elz, R., Bush, R., "Clarifications to the DNS Specification",
RFC2181, July 1997. RFC2181, July 1997.
[RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", RFC2671, [RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", RFC2671,
August 1999. August 1999.
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Authors' Addresses 10 - Authors' Addresses
Paul Vixie Paul Vixie
950 Charter Street 950 Charter Street
Redwood City, CA 94063 Redwood City, CA 94063
+1 650 423 1301 +1 650 423 1301
vixie@isc.org vixie@isc.org
Akira Kato Akira Kato
University of Tokyo, Information Technology Center University of Tokyo, Information Technology Center
2-11-16 Yayoi Bunkyo 2-11-16 Yayoi Bunkyo
skipping to change at page 10, line 4 skipping to change at page 12, line 4
pertain to the implementation or use of the technology described in this pertain to the implementation or use of the technology described in this
document or the extent to which any license under such rights might or document or the extent to which any license under such rights might or
might not be available; nor does it represent that it has made any might not be available; nor does it represent that it has made any
independent effort to identify any such rights. Information on the independent effort to identify any such rights. Information on the
procedures with respect to rights in RFC documents can be found in BCP procedures with respect to rights in RFC documents can be found in BCP
78 and BCP 79. 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an attempt assurances of licenses to be made available, or the result of an attempt
made to obtain a general license or permission for the use of such made to obtain a general license or permission for the use of such
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proprietary rights by implementers or users of this specification can be proprietary rights by implementers or users of this specification can be
obtained from the IETF on-line IPR repository at obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary rights copyrights, patents or patent applications, or other proprietary rights
that may cover technology that may be required to implement this that may cover technology that may be required to implement this
standard. Please address the information to the IETF at standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
 End of changes. 34 change blocks. 
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