<?xml version='1.0'encoding='utf-8'?>encoding='UTF-8'?> <!DOCTYPE rfc [ <!ENTITY nbsp " "> <!ENTITY zwsp "​"> <!ENTITY nbhy "‑"> <!ENTITY wj "⁠"> ]><?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?> <!-- generated by https://github.com/cabo/kramdown-rfc version 1.7.2 (Ruby 3.2.2) --><rfc xmlns:xi="http://www.w3.org/2001/XInclude" ipr="trust200902" docName="draft-ietf-opsawg-rfc7125-update-07" number="9565" category="std" consensus="true" submissionType="IETF" obsoletes="7125" updates="" tocInclude="true" sortRefs="true" symRefs="true"version="3"> <!-- xml2rfc v2v3 conversion 3.18.2 -->version="3" xml:lang="en"> <front> <title abbrev="tcpControlBitsIPFIX">AnIPFIX Information Element">An Update to the tcpControlBits IP Flow Information Export (IPFIX) Information Element</title> <seriesInfoname="Internet-Draft" value="draft-ietf-opsawg-rfc7125-update-07"/>name="RFC" value="9565"/> <author fullname="Mohamed Boucadair"> <organization>Orange</organization> <address> <postal> <city>Rennes</city> <code>35000</code> <country>France</country> </postal> <email>mohamed.boucadair@orange.com</email> </address> </author> <dateyear="2023" month="November" day="29"/>year="2024" month="March"/> <area>Operations and Management</area> <workgroup>OPSAWG</workgroup> <keyword>IPFIX</keyword> <keyword>TCP</keyword> <keyword>Measurement</keyword> <keyword>Export</keyword> <keyword>Observability</keyword> <abstract><?line 45?><t>RFC 7125 revised the tcpControlBits IP Flow Information Export (IPFIX) Information Element that was originally defined in RFC 5102 to reflect changes to the TCP header control bits since RFC 793. However, that update is still problematic for interoperability because some flag values have subsequently been deprecated.</t> <t>This document removes stale information from theIPFIXIANA "IPFIX Information Elements" registry and avoids future conflicts with the authoritativeTCPIANA "TCP HeaderFlagsFlags" registry.</t> <t>This document obsoletes RFC 7125.</t> </abstract><note removeInRFC="true"> <name>Discussion Venues</name> <t>Discussion of this document takes place on the Operations and Management Area Working Group Working Group mailing list (opsawg@ietf.org), which is archived at <eref target="https://mailarchive.ietf.org/arch/browse/opsawg/"/>.</t> <t>Source for this draft and an issue tracker can be found at <eref target="https://github.com/boucadair/-ipfix-rfc7125-update"/>.</t> </note></front> <middle> <?line 59?> <section anchor="introduction"> <name>Introduction</name> <t>TCP defines a set of control bits (also known as "flags") for managing connections (<xref section="3.1" sectionFormat="of" target="RFC9293"/>). The"Transmission Control Protocol (TCP)"TCP Header Flags" registry was initially set by <xref target="RFC3168"/>, but it was populated with only TCP control bits that were defined in <xref target="RFC3168"/>. <xref target="RFC9293"/> fixed that by moving that registry to be listed as a subregistry under the "Transmission Control Protocol (TCP) Parameters" registry <xref target="TCP-FLAGS"/>, adding bits that had previously been specified in <xref target="RFC0793"/>, and removing the NS (Nonce Sum) bitasper <xref target="RFC8311"/>. Also, <xref section="6" sectionFormat="of" target="RFC9293"/> introduces "Bit Offset" to ease referencing each header flag's offset within the 16-bit aligned view of the TCP header (Figure 1 of <xref target="RFC9293"/>). <xref target="TCP-FLAGS"/> is thus settled as the authoritative reference for the assigned TCP control bits.</t><ul empty="true"> <li> <t>Note:<t indent="3">Note: The bits in offsets 0 through 3 are not header flags, but the TCP segment Data Offset field.</t></li> </ul><t><xref target="RFC7125"/> revised the tcpControlBits IP Flow Information Export (IPFIX) Information Element(IE)that was originally defined in <xref target="RFC5102"/> to reflect changes to the TCP control bits since <xref target="RFC0793"/>. However, that update is still problematic for interoperability because a value was deprecated since then (<xref section="7" sectionFormat="of"target="RFC8311"/>)target="RFC8311"/>), and, therefore, <xref target="RFC7125"/> risks deviating from the authoritativeTCP"TCP Header Flags" registry <xref target="TCP-FLAGS"/>.</t> <t>This document fixes that problem by removing stale information from theIPFIX"IPFIX Information Elements" registry <xref target="IPFIX"/> and avoiding future conflicts with the authoritativeTCP"TCP Header Flags" registry <xref target="TCP-FLAGS"/>. The update in this documentisalsouseful to enhanceenhances observability. For example, network operators can identifywhenpackets that arebeingobserved with unassigned TCP flags set and, therefore, identify which applications in the network should be upgraded to reflect the changes to TCP flags that were introduced, e.g., in <xref target="RFC8311"/>.</t> <t>The main changestofrom <xref target="RFC7125"/> are listed in <xref target="changes"/>.</t> </section> <section anchor="terminology"> <name>Terminology</name> <t>The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described inBCP 14BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they appear in all capitals, as shown here.</t><?line -18?><t>This document uses the terms defined inSection 2 of<xreftarget="RFC7011"/>.</t>target="RFC7011" section="2" sectionFormat="of"/>.</t> </section> <section anchor="revised-tcpcontrolbits-information-element"> <name>Revised tcpControlBits Information Element</name> <dl><dt>ElementId:</dt><dt>ElementID:</dt> <dd> <t>6</t> </dd><dt>Data<dt>Name:</dt> <dd> <t>tcpControlBits</t> </dd> <dt>Abstract Data Type:</dt> <dd> <t>unsigned16</t> </dd> <dt>Data Type Semantics:</dt> <dd> <t>flags</t> </dd> <dt>Status:</dt> <dd> <t>current</t> </dd> <dt>Description:</dt> <dd> <t>TCP control bits observed for the packets of this Flow. This information is encoded as a bit field; each TCP control bit has a corresponding bit in that field. A bit is set to 1 if any observed packet of this Flow has the corresponding TCP control bit set to 1. The bit is cleared to 0 otherwise.</t></dd> <dt/> <dd> <t>As per<t>Per <xref target="RFC9293"/>, the assignment oftheTCP control bits is managed by IANAfromvia the "TCP Header Flags" registry <xref target="TCP-FLAGS"/>.That registry is authoritative toImplementers can retrieve themost recentcurrent TCP controlbits.</t> </dd> <dt/> <dd>bits from that registry, which is authoritative for them.</t> <t>As the most significant 4 bits of octets 12 and 13 (counting from zero) of the TCP header <xref target="RFC9293"/> are used to encode the TCP data offset (header length), the corresponding bits in this Information Element <bcp14>MUST</bcp14> be reported by the Exporter with a value of zero and <bcp14>MUST</bcp14> be ignored by the Collector. Use the tcpHeaderLength Information Element to encode this value.</t></dd> <dt/> <dd><t>All TCP control bits (including those unassigned) <bcp14>MUST</bcp14> be exported as observed in the TCP headers of the packets of this Flow.</t></dd> <dt/> <dd><t>If exported as a single octet with reduced-size encoding (<xref section="6.2" sectionFormat="of" target="RFC7011"/>), this Information Element covers the low-order octet of this field (i.e., bit offset positions 8 to 15) <xref target="TCP-FLAGS"/>. A Collector receiving this Information Element with reduced-size encoding must not assume anything about the content of the four bits with bit offset positions 4 to 7.</t></dd> <dt/> <dd><t>Exporting Processes exporting this Information Element on behalf of a Metering Process that is not capable of observing any of the flags with bit offset positions 4 to 7 <bcp14>SHOULD</bcp14> use reduced-size encoding, and only export the least significant 8 bits of this Information Element.</t></dd> <dt/> <dd><t>Note that previous revisions of this Information Element's definition specified that flags with bit offset positions 8 and 9 must be exported as zero, even if observed. Collectors should therefore not assume that a value of zero for these bits in this Information Element indicates the bits were never set in the observed traffic, especially if these bits are zero in every Flow Record sent by a given Exporter.</t></dd> <dt/> <dd><t>Note also that the "TCP Header Flags" registry <xref target="TCP-FLAGS"/> indexes the bit offset from themost-significantmost significant bit of octet 12 to theleast-significantleast significant bit of octet 13 in the TCP header, but the tcpControlBits is encoded as a regular unsigned16 bit16-bit integer.</t> </dd></dl> <t>Units:</t> <t>Range:</t> <dl> <dt>References:</dt> <dd> <t><xref target="RFC9293"/>[This-Document]</t> </dd><dt>Units:</dt> <dd/> <dt>Range:</dt> <dd/> <dt>Additional Information:</dt> <dd> <t>See the assigned TCP control bits in the "TCP Header Flags" registry <xref target="TCP-FLAGS"/>.</t> </dd> <dt>Reference:</dt> <dd> <t><xref target="RFC9293"/>, RFC 9565</t> </dd> <dt>Revision:</dt> <dd> <t>2</t> </dd> </dl> </section> <section anchor="an-example"> <name>An Example</name> <t><xref target="ex"/> shows an example of a tcpControlBits Information Element set to146.0x92, where MSB indicates the most significant bit and LSB indicates the least significant bit. This Information Element is used to report TCP control bits for a Flow that has CWR (Congestion Window Reduced), ACK, and SYN flag bits set (that is, bit offset positions 8, 11, and 14).</t> <figure anchor="ex"> <name>An Example of the tcpControlBits Information Element</name> <artwork align="center"><![CDATA[ MSB LSB 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|0|0|0|0|0|0|0|1|0|0|1|0|0|1|0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ]]></artwork> </figure> </section> <section anchor="iana-considerations"> <name>IANA Considerations</name> <t>IANAis requested to updatehas updated the "tcpControlBits" entry of the "IPFIX Information Elements" registry <xref target="IPFIX"/> to echo the details provided inSection 3.</t><xref target="revised-tcpcontrolbits-information-element"/>.</t> </section> <section anchor="security-considerations"> <name>Security Considerations</name> <t>Because the setting of TCP control bits may be misused in someflowsFlows (e.g., Distributed Denial-of-Service (DDoS) attacks), an Exporter has to report all observed control bits even if no meaning is associated with a given TCP flag. This document uses a stronger requirements language compared to <xref target="RFC7125"/>.</t> <t>This document does not add new security considerations to those already discussed for IPFIX in <xref target="RFC7011"/>.</t> </section> </middle> <back> <references> <name>References</name> <references anchor="sec-normative-references"> <name>Normative References</name> <reference anchor="TCP-FLAGS"target="https://www.iana.org/assignments/tcp-parameters/tcp-parameters.xhtml#tcp-header-flags">target="https://www.iana.org/assignments/tcp-parameters/"> <front> <title>TCP Header Flags</title> <author> <organization>IANA</organization> </author><date>n.d.</date> </front> </reference> <reference anchor="RFC9293"> <front> <title>Transmission Control Protocol (TCP)</title> <author fullname="W. Eddy" initials="W." role="editor" surname="Eddy"/> <date month="August" year="2022"/> <abstract> <t>This document specifies the Transmission Control Protocol (TCP). TCP is an important transport-layer protocol in the Internet protocol stack, and it has continuously evolved over decades of use and growth of the Internet. Over this time, a number of changes have been made to TCP as it was specified in RFC 793, though these have only been documented in a piecemeal fashion. This document collects and brings those changes together with the protocol specification from RFC 793. This document obsoletes RFC 793, as well as RFCs 879, 2873, 6093, 6429, 6528, and 6691 that updated parts of RFC 793. It updates RFCs 1011 and 1122, and it should be considered as a replacement for the portions of those documents dealing with TCP requirements. It also updates RFC 5961 by adding a small clarification in reset handling while in the SYN-RECEIVED state. The TCP header control bits from RFC 793 have also been updated based on RFC 3168.</t> </abstract> </front> <seriesInfo name="STD" value="7"/> <seriesInfo name="RFC" value="9293"/> <seriesInfo name="DOI" value="10.17487/RFC9293"/> </reference> <reference anchor="RFC2119"> <front> <title>Key words for use in RFCs to Indicate Requirement Levels</title> <author fullname="S. Bradner" initials="S." surname="Bradner"/> <date month="March" year="1997"/> <abstract> <t>In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t> </abstract></front><seriesInfo name="BCP" value="14"/> <seriesInfo name="RFC" value="2119"/> <seriesInfo name="DOI" value="10.17487/RFC2119"/> </reference> <reference anchor="RFC8174"> <front> <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title> <author fullname="B. Leiba" initials="B." surname="Leiba"/> <date month="May" year="2017"/> <abstract> <t>RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t> </abstract> </front> <seriesInfo name="BCP" value="14"/> <seriesInfo name="RFC" value="8174"/> <seriesInfo name="DOI" value="10.17487/RFC8174"/> </reference> <reference anchor="RFC7011"> <front> <title>Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information</title> <author fullname="B. Claise" initials="B." role="editor" surname="Claise"/> <author fullname="B. Trammell" initials="B." role="editor" surname="Trammell"/> <author fullname="P. Aitken" initials="P." surname="Aitken"/> <date month="September" year="2013"/> <abstract> <t>This document specifies the IP Flow Information Export (IPFIX) protocol, which serves as a means for transmitting Traffic Flow information over the network. In order to transmit Traffic Flow information from an Exporting Process to a Collecting Process, a common representation of flow data and a standard means of communicating them are required. This document describes how the IPFIX Data and Template Records are carried over a number of transport protocols from an IPFIX Exporting Process to an IPFIX Collecting Process. This document obsoletes RFC 5101.</t> </abstract> </front> <seriesInfo name="STD" value="77"/> <seriesInfo name="RFC" value="7011"/> <seriesInfo name="DOI" value="10.17487/RFC7011"/></reference> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9293.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7011.xml"/> </references> <references anchor="sec-informative-references"> <name>Informative References</name> <reference anchor="IPFIX"target="https://www.iana.org/assignments/ipfix/ipfix.xhtml">target="https://www.iana.org/assignments/ipfix/"> <front><title>IP Flow<title>IPFIX InformationExport (IPFIX) Entities</title>Elements</title> <author> <organization>IANA</organization> </author><date>n.d.</date> </front> </reference> <reference anchor="RFC3168"> <front> <title>The Addition of Explicit Congestion Notification (ECN) to IP</title> <author fullname="K. Ramakrishnan" initials="K." surname="Ramakrishnan"/> <author fullname="S. Floyd" initials="S." surname="Floyd"/> <author fullname="D. Black" initials="D." surname="Black"/> <date month="September" year="2001"/> <abstract> <t>This memo specifies the incorporation of ECN (Explicit Congestion Notification) to TCP and IP, including ECN's use of two bits in the IP header. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="3168"/> <seriesInfo name="DOI" value="10.17487/RFC3168"/> </reference> <reference anchor="RFC0793"> <front> <title>Transmission Control Protocol</title> <author fullname="J. Postel" initials="J." surname="Postel"/> <date month="September" year="1981"/> </front> <seriesInfo name="RFC" value="793"/> <seriesInfo name="DOI" value="10.17487/RFC0793"/> </reference> <reference anchor="RFC8311"> <front> <title>Relaxing Restrictions on Explicit Congestion Notification (ECN) Experimentation</title> <author fullname="D. Black" initials="D." surname="Black"/> <date month="January" year="2018"/> <abstract> <t>This memo updates RFC 3168, which specifies Explicit Congestion Notification (ECN) as an alternative to packet drops for indicating network congestion to endpoints. It relaxes restrictions in RFC 3168 that hinder experimentation towards benefits beyond just removal of loss. This memo summarizes the anticipated areas of experimentation and updates RFC 3168 to enable experimentation in these areas. An Experimental RFC in the IETF document stream is required to take advantage of any of these enabling updates. In addition, this memo makes related updates to the ECN specifications for RTP in RFC 6679 and for the Datagram Congestion Control Protocol (DCCP) in RFCs 4341, 4342, and 5622. This memo also records the conclusion of the ECN nonce experiment in RFC 3540 and provides the rationale for reclassification of RFC 3540 from Experimental to Historic; this reclassification enables new experimental use of the ECT(1) codepoint.</t> </abstract></front><seriesInfo name="RFC" value="8311"/> <seriesInfo name="DOI" value="10.17487/RFC8311"/> </reference> <reference anchor="RFC7125"> <front> <title>Revision of the tcpControlBits IP Flow Information Export (IPFIX) Information Element</title> <author fullname="B. Trammell" initials="B." surname="Trammell"/> <author fullname="P. Aitken" initials="P." surname="Aitken"/> <date month="February" year="2014"/> <abstract> <t>This document revises the tcpControlBits IP Flow Information Export (IPFIX) Information Element as originally defined in RFC 5102 to reflect changes to the TCP Flags header field since RFC 793.</t> </abstract> </front> <seriesInfo name="RFC" value="7125"/> <seriesInfo name="DOI" value="10.17487/RFC7125"/> </reference> <reference anchor="RFC5102"> <front> <title>Information Model for IP Flow Information Export</title> <author fullname="J. Quittek" initials="J." surname="Quittek"/> <author fullname="S. Bryant" initials="S." surname="Bryant"/> <author fullname="B. Claise" initials="B." surname="Claise"/> <author fullname="P. Aitken" initials="P." surname="Aitken"/> <author fullname="J. Meyer" initials="J." surname="Meyer"/> <date month="January" year="2008"/> <abstract> <t>This memo defines an information model for the IP Flow Information eXport (IPFIX) protocol. It is used by the IPFIX protocol for encoding measured traffic information and information related to the traffic Observation Point, the traffic Metering Process, and the Exporting Process. Although developed for the IPFIX protocol, the model is defined in an open way that easily allows using it in other protocols, interfaces, and applications. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="5102"/> <seriesInfo name="DOI" value="10.17487/RFC5102"/> </reference> <reference anchor="RFC9487"> <front> <title>Export of Segment Routing over IPv6 Information in IP Flow Information Export (IPFIX)</title> <author fullname="T. Graf" initials="T." surname="Graf"/> <author fullname="B. Claise" initials="B." surname="Claise"/> <author fullname="P. Francois" initials="P." surname="Francois"/> <date month="November" year="2023"/> <abstract> <t>This document introduces new IP Flow Information Export (IPFIX) Information Elements (IEs) to identify a set of information related to Segment Routing over IPv6 (SRv6) such as data contained in a Segment Routing Header (SRH), the SRv6 control plane, and the SRv6 Endpoint behavior that traffic is being forwarded with.</t> </abstract> </front> <seriesInfo name="RFC" value="9487"/> <seriesInfo name="DOI" value="10.17487/RFC9487"/></reference> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3168.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.0793.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8311.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7125.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5102.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9487.xml"/> </references> </references><?line 222?><section anchor="changes"> <name>Changes from RFC 7125</name> <ul spacing="normal"> <li><t>Clean-up<t>Cleaned up the description of the tcpControlBits Information Element by removing mentions of stale flag bits, referring to the flag bits by their bit offset position, and relying upon the IANATCP"TCP Header Flags" registry.</t> </li> <li><t>Remove<t>Removed the table of TCP flag bits from the description of the tcpControlBits Information Element.</t> </li> <li><t>Add<t>Added the reference <xref target="TCP-FLAGS"/> to the Additional Information field of the tcpControlBits Information Element.</t> </li> <li><t>Use<t>Used strong normative language for exporting observed flags.</t> </li> <li><t>Update<t>Updated the references of the tcpControlBits Information Element.</t> </li> <li><t>Bump<t>Bumped the revision of the tcpControlBits Information Element.</t> </li> <li><t>Replace<t>Replaced obsolete RFCs (e.g., <xref target="RFC0793"/>).</t> </li> <li><t>Add<t>Added anExample Section</t>example section (<xref target="an-example"/>).</t> </li> </ul> </section> <section numbered="false" anchor="acknowledgments"> <name>Acknowledgments</name> <t>This document was triggered by a discussionof the authorin the opsawgwithworking group between the author and the authors of <xref target="RFC9487"/>.</t> <t>Thanks toChristian Jacquenet, Thomas Graf, and Benoît Claise<contact fullname="Christian Jacquenet"/>, <contact fullname="Thomas Graf"/>, and <contact fullname="Benoît Claise"/> for the review and comments.</t> <t>Thanks toMichael Scharf<contact fullname="Michael Scharf"/> for the tsvart review,Ketan Talaulikar<contact fullname="Ketan Talaulikar"/> for the rtgdir review, andElwyn Davies<contact fullname="Elwyn Davies"/> for the genart review.</t> <t>Thanks toRob Wilton<contact fullname="Rob Wilton"/> for the AD review.</t> <t>Thanksfor Tim Brayto <contact fullname="Tim Bray"/> for the artart review andShawn Emery<contact fullname="Shawn Emery"/> for the secdir review.</t> <t>Thanks toÉric Vyncke and Paul Wouters<contact fullname="Éric Vyncke"/> and <contact fullname="Paul Wouters"/> for the comments in the IESG review.</t><dl> <dt>Acknowledgments<section numbered="false" anchor="acknowledgments7125"> <name>Acknowledgments from<xref target="RFC7125"/>:</dt> <dd>RFC 7125</name> <t>Thanks toAndrew Feren, Lothar Braun, Michael Scharf, and Simon Josefsson<contact fullname="Andrew Feren"/>, <contact fullname="Lothar Braun"/>, <contact fullname="Michael Scharf"/>, and <contact fullname="Simon Josefsson"/> for comments on the revised definition. This work is partially supported by the European Commission under grant agreement FP7-ICT-318627 mPlane; this does not imply endorsement by the Commission.</t></dd> </dl></section> </section> <section numbered="false" anchor="contributors"> <name>Contributors</name> <t>The authors of <xref target="RFC7125"/> are as follows:</t><ul spacing="normal"> <li> <t>Brian Trammell</t> </li> <li> <t>Paul Aitken</t> </li> </ul><contact fullname="Brian Trammell"> <organization/> </contact> <contact fullname="Paul Aitken"> <organization/> </contact> </section> </back><!-- ##markdown-source: H4sIAAAAAAAAA7Va23LbyBF9x1dM6IeVNiQtSrIkc2+hbrZ2dYsox9na2och MCSnBGK4GEC0Vuu85y/yBfmI7I/ldM8MAFK0va5K5CqLAAc9fT19eqBOpxMV ukhVX7QGmXgzT2ShRGFEMcWveH5ksiI36aEurDi7FqepWYizbGzymSy0ycTJ u7nJC7Fxdn169vfN5a9SNVNZ0YrkaJSre2zwRB6eaUUxdpyY/KEvbJFEZmRN qgpl+2K/t/0iihITZ3IG/ZJcjouOVsW4Y+ZWLiadfBzTmk7JWne29iNbjmba WmxfPMzxzNnJ7WmUlbORyvsRLepHscmsymyJDYq8VBEU24lkriQUvJqrnJW3 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