Re: [IPFIX] templateLifePacket on IPFIX collector
Petr Velan <[email protected]> Mon, 2 Oct 2017 15:24:17 +0200
| Newsgroups | gmane.ietf.ipfix |
|---|---|
| Message-ID | <CALbOe5M+YzXN8VPKBU_04ZGxk43bauyfbZspiRUcFAjXeO4JOA@mail.gmail.com> |
--===============1939123794526503692== Content-Type: multipart/alternative; boundary="94eb2c0e71fca8fb96055a904a33" --94eb2c0e71fca8fb96055a904a33 Content-Type: text/plain; charset="UTF-8" Hi Benoit, I think that there is a slight confusion. I'm talking specifically about __Collection Process__, not __Exporting Process__. My focus is on templateLifeTime, optionsTemplateLifeTime, templateLifePacket, and optionsTemplateLifePacket options and not at all about templateRefreshTimeout, optionsTemplateRefreshTimeout, templateRefreshPacket, and optionsTemplateRefreshPacket options. With that cleared out, let my try to clarify: On Mon, Oct 2, 2017 at 2:11 PM, Benoit Claise <[email protected]> wrote: > Hi Petr, > > Hi Brian, > > I understand that the Exporter is required to export the templates at > regular intervals. It is not clear, whether "regular intervals" mean "time > intervals" (as suggested by the templateRefreshTimeout example) or if it > can mean "packet intervals" as well (as suggested by the RFC 6728). > > As mentioned, the two options come from NetFlow v9, with UDP. > > Moreover, this discusses only the Exporter Processes. My question was > primarily about the Collecting Process, where the RFC 7011 specifies the > following: > > In order to minimize resource requirements for Templates that are no > longer being used by the Exporting Process, the Collecting Process > MAY associate a lifetime with each Template received in a Transport > Session. Templates not refreshed by the Exporting Process within the > lifetime can then be discarded by the Collecting Process. The > Template lifetime at the Collecting Process MAY be exposed by a > configuration parameter or MAY be derived from observation of the > interval of periodic Template retransmissions from the Exporting > Process. In this latter case, the Template lifetime SHOULD default > to at least 3 times the observed retransmission rate. > > So the IPFIX configuration model only suggests that the Collecting Process > can use the *TemplateLifePacket options without actually requiring their > implementation anywhere. Is that correct? > > Not sure I understand. > From RFC7011 > > Since UDP provides no method for reliable transmission of Templates, > Exporting Processes using UDP as the transport protocol MUST > periodically retransmit each active Template at regular intervals. > The Template retransmission interval MUST be configurable via, for > example, the templateRefreshTimeout and optionsTemplateRefreshTimeout > parameters as defined in [RFC6728 <https://tools.ietf.org/html/rfc6728>]. Default settings for these > values are deployment- and application-specific. > > > If the collector is the one that configured the templateRefreshTimeout and > optionsTemplateRefreshTimeout for the Exporter, then it knows this > information. Alternatively, it can try to deduce it. > > This says that an __Exporting Process__ must implement some kind of the template refresh timeout for UDP and that it must be configurable. However, template lifetime tracking is only suggested for __Collecting Processes__ for the UDP protocol in the RFC 7011 and the template lifepacket expiration is not mentioned at all. My original question was whether the template lifepacket tracking was required/suggested by the IPFIX protocol as it was present in the IPFIX information model. The answer to that question seems to be _no_. > Now, an editorial errata (more for completeness that anything else) could > be that RFC7011 should mention RFC 6728 templateRefreshPacket and > optionsTemplateRefreshPacket. > However, it says "for example, the templateRefreshTimeout and > optionsTemplateRefreshTimeout parameters as defined in [RFC6728 > <https://tools.ietf.org/html/rfc6728>]." > So there might be other examples. > > > On a related note, while reading through the RFC 6728, I've noticed that > it still references the obsoleted RFC 5101, which is not good, especially > regarding the template timeout on collecting process. The problem is that > it forces the configuration of templateLifeTime and optionsTemplateLifeTime > options per RFC 5101, Section 10.3.7 where it states: > > The Collecting Process MUST associate a lifetime with each Template > (or another definition of an identifier considered unique within the > Transport Session) received via UDP. Templates (and similar > definitions) not refreshed by the Exporting Process within the > lifetime are expired at the Collecting Process. > > However, the RFC 7011 obsoletes this (see my first quote) and changes this > behaviour to optional. Would it make sense to update the RFC 6728 to > reflect this change? > > Maybe. > That is a significant change from RFC 5101 which _required_ the template lifetime tracking. The relevant text in RFC 6728 stil references RFC 5101 and suggest that implementing the template lifetime expiration for UDP it is still required for __Collecting Processes_ by the IPFIX protocol, which is no longer true. The template expiration based on number of packets at the __Collecting Process__ was not present anywhere in the RFC 3954. Therefore, I'm surprised to find it in the IPFIX information model when it is not mentioned in the standard. I fully agree that the templateRefreshPacket makes complete sense at the __Exporting Process__, but my focus here is on the __Collecting Process__. Cheers, Petr > > Regards, Benoit > > > Cheers, > Petr > > On Mon, Oct 2, 2017 at 10:05 AM, Brian Trammell (IETF) <[email protected]> > wrote: > >> hi Petr, >> >> This is specified in section 8.4 of RFC 7011 for UDP: >> >> Since UDP provides no method for reliable transmission of Templates, >> Exporting Processes using UDP as the transport protocol MUST >> periodically retransmit each active Template at regular intervals. >> The Template retransmission interval MUST be configurable via, for >> example, the templateRefreshTimeout and optionsTemplateRefreshTimeout >> parameters as defined in [RFC6728]. Default settings for these >> values are deployment- and application-specific. >> >> For transports with reliable template lifetimes (TCP, SCTP), templates >> require no refresh, since template state remains synchronized between >> exporter and collector. >> >> Cheers, >> >> Brian >> >> >> > On 2 Oct 2017, at 09:37, Petr Velan <[email protected]> wrote: >> > >> > Hello IPFIX masters, >> > >> > we are implementing an IPFIX collector and a question came up whether >> to support templateLifePacket configuration as specified in RFC 6728 ( >> https://tools.ietf.org/html/rfc6728#section-4.5.2). It seems, that the >> *LifePacket options are not mentioned anywhere else in the IPFIX related >> documents and that the IPFIX protocol specifies only time based timeout >> expiration. Therefore, my question is why the *LifePacket options are even >> present in the RFC 6728 and whether it is necessary to implement them for >> the collector (and exporter as well) to be compliant with the IPFIX >> standard. >> > >> > I think that the whole *LifePacket option came from NetFlow v9 where >> the informational RFC 3954 states that: >> > On a regular basis, the Exporter MUST send all the Template >> > Records and Options Template Records to refresh the Collector. >> > Template IDs have a limited lifetime at the Collector and MUST be >> > periodically refreshed. Two approaches are taken to make sure >> > that Templates get refreshed at the Collector: >> > * Every N number of Export Packets. >> > * On a time basis, so every N number of minutes. >> > Both options MUST be configurable by the user on the Exporter. >> > When one of these expiry conditions is met, the Exporter MUST send >> > the Template FlowSet and Options Template. >> > >> > >> > If that is the case, should the IPFIX standard specify something >> similar as well? Otherwise, it would seem that removing the *LifePacket >> options from the RFC 6728 would prevent further confusion. >> > >> > Kind regards, >> > Petr Velan >> > >> > _______________________________________________ >> > IPFIX mailing list >> > [email protected] >> > https://www.ietf.org/mailman/listinfo/ipfix >> >> > > > _______________________________________________ > IPFIX mailing [email protected]://www.ietf.org/mailman/listinfo/ipfix > > > --94eb2c0e71fca8fb96055a904a33 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div><div>Hi Benoit,<br><br></div>I think that there is a = slight confusion. I'm talking specifically about __Collection Process__= , not __Exporting Process__. My focus is on templateLifeTime, optionsTempla= teLifeTime, templateLifePacket, and optionsTemplateLifePacket options and n= ot at all about templateRefreshTimeout, optionsTemplateRefreshTimeout, temp= lateRefreshPacket, and optionsTemplateRefreshPacket options.<br><br></div>W= ith that cleared out, let my try to clarify:<br><div><br><div><div class=3D= "gmail_extra"><div class=3D"gmail_quote">On Mon, Oct 2, 2017 at 2:11 PM, Be= noit Claise <span dir=3D"ltr"><<a href=3D"mailto:[email protected]" targ= et=3D"_blank">[email protected]</a>></span> wrote:<br><blockquote class= =3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rg= b(204,204,204);padding-left:1ex"> =20 =20 =20 <div bgcolor=3D"#FFFFFF"> <div class=3D"gmail-m_-6801902955678215617moz-cite-prefix">Hi Petr,<br> </div><span class=3D"gmail-"> <blockquote type=3D"cite"> =20 <div dir=3D"ltr"> <div> <div> <div> <div>Hi Brian,<br> <br> </div> I understand that the Exporter is required to export the templates at regular intervals. It is not clear, whether "regular intervals" mean "time intervals"= (as suggested by the templateRefreshTimeout example) or if it can mean "packet intervals" as well (as suggested by the RFC= 6728). </div> </div> </div> </div> </blockquote></span> As mentioned, the two options come from NetFlow v9, with UDP.<span clas= s=3D"gmail-"><br> <blockquote type=3D"cite"> <div dir=3D"ltr"> <div> <div> <div>Moreover, this discusses only the Exporter Processes. My question was primarily about the Collecting Process, where the RFC 7011 specifies the following:<br> <br> <pre class=3D"gmail-m_-6801902955678215617gmail-newpage"> I= n order to minimize resource requirements for Templates that are no longer being used by the Exporting Process, the Collecting Process MAY associate a lifetime with each Template received in a Transport Session. Templates not refreshed by the Exporting Process within the lifetime can then be discarded by the Collecting Process. The Template lifetime at the Collecting Process MAY be exposed by a configuration parameter or MAY be derived from observation of the interval of periodic Template retransmissions from the Exporting Process. In this latter case, the Template lifetime SHOULD default to at least 3 times the observed retransmission rate.<span style=3D"font= -family:arial,helvetica,sans-serif"> </span></pre> So the IPFIX configuration model only suggests that the Collecting Process can use the *TemplateLifePacket options without actually requiring their implementation anywhere. Is that correct?<br> </div> </div> </div> </div> </blockquote></span> Not sure I understand.<br> From RFC7011<span class=3D"gmail-"><br> <pre class=3D"gmail-m_-6801902955678215617newpage"> Since UDP provide= s no method for reliable transmission of Templates, Exporting Processes using UDP as the transport protocol MUST periodically retransmit each active Template at regular intervals. The Template retransmission interval MUST be configurable via, for example, the templateRefreshTimeout and optionsTemplateRefreshTimeout parameters as defined in [<a href=3D"https://tools.ietf.org/html/rfc6728= " title=3D""Configuration Data Model for the IP Flow Information Expor= t (IPFIX) and Packet Sampling (PSAMP) Protocols"" target=3D"_blank">RF= C6728</a>]. Default settings for these values are deployment- and application-specific. </pre></span> If the collector is the one that configured the templateRefreshTimeout and optionsTemplateRefreshTimeout for the Exporter, then it knows this information. Alternatively, it can try to deduce it.<br> <br></div></blockquote><div>This says that an __Exporting Process__ mus= t implement some kind of the template refresh timeout for UDP and that it m= ust be configurable. However, template lifetime tracking is only suggested = for __Collecting Processes__ for the UDP protocol in the RFC 7011 and the t= emplate lifepacket expiration is not mentioned at all. My original question= was whether the template lifepacket tracking was required/suggested by the= IPFIX protocol as it was present in the IPFIX information model. The answe= r to that question seems to be _no_.<br>=C2=A0</div><blockquote class=3D"gm= ail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,= 204,204);padding-left:1ex"><div bgcolor=3D"#FFFFFF"> Now, an editorial errata (more for completeness that anything else) could be that RFC7011 should mention RFC 6728 templateRefreshPacket and optionsTemplateRefreshPacket.<br> However, it says "for example, the templateRefreshTimeout and optionsTemplateRefreshTimeout parameters as defined in [<a href=3D"http= s://tools.ietf.org/html/rfc6728" title=3D""Configuration Data Model fo= r the IP Flow Information Export (IPFIX) and Packet Sampling (PSAMP) Protocols"" target=3D= "_blank">RFC6728</a>]."<br> So there might be other examples.<span class=3D"gmail-"><br> <blockquote type=3D"cite"> <div dir=3D"ltr"> <div> <div> <div><br> On a related note, while reading through the RFC 6728, I've noticed that it still references the obsoleted RFC 5101, which is not good, especially regarding the template timeout on collecting process. The problem is that it forces the configuration of templateLifeTime and optionsTemplateLifeTime options per RFC 5101, Section 10.3.7 where it states:<br> <pre class=3D"gmail-m_-6801902955678215617gmail-newpage"> T= he Collecting Process MUST associate a lifetime with each Template (or another definition of an identifier considered unique within the Transport Session) received via UDP. Templates (and similar definitions) not refreshed by the Exporting Process within the lifetime are expired at the Collecting Process.</pre> </div> However, the RFC 7011 obsoletes this (see my first quote) and changes this behaviour to optional. Would it make sense to update the RFC 6728 to reflect this change?<br> </div> </div> </div> </blockquote></span> Maybe.<br></div></blockquote><div><br>That is a significant change from= RFC 5101 which _required_ the template lifetime tracking. The relevant tex= t in RFC 6728=20 stil references RFC 5101 and suggest that implementing the template=20 lifetime expiration for UDP it is still required for __Collecting=20 Processes_ by the IPFIX protocol, which is no longer true. <br><br>The temp= late expiration based on number of packets at the __Collecting Process__ wa= s not present anywhere in the RFC 3954. Therefore, I'm surprised to fin= d it in the IPFIX information model when it is not mentioned in the standar= d. I fully agree that the templateRefreshPacket makes complete sense at the= __Exporting Process__, but my focus here is on the __Collecting Process__.= <br><br></div><div>Cheers,<br></div><div>Petr<br></div><blockquote class=3D= "gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(2= 04,204,204);padding-left:1ex"><div bgcolor=3D"#FFFFFF"> <br> Regards, Benoit<div><div class=3D"gmail-h5"><br> <blockquote type=3D"cite"> <div dir=3D"ltr"> <div> <div><br> </div> Cheers,<br> </div> Petr<br> </div> <div class=3D"gmail_extra"><br> <div class=3D"gmail_quote">On Mon, Oct 2, 2017 at 10:05 AM, Brian Trammell (IETF) <span dir=3D"ltr"><<a href=3D"mailto:ietf@tram= mell.ch" target=3D"_blank">[email protected]</a>></span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8= ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">hi Petr,<br> <br> This is specified in section 8.4 of RFC 7011 for UDP:<br> <br> =C2=A0 =C2=A0Since UDP provides no method for reliable transmis= sion of Templates,<br> =C2=A0 =C2=A0Exporting Processes using UDP as the transport pro= tocol MUST<br> =C2=A0 =C2=A0periodically retransmit each active Template at re= gular intervals.<br> =C2=A0 =C2=A0The Template retransmission interval MUST be confi= gurable via, for<br> =C2=A0 =C2=A0example, the templateRefreshTimeout and optionsTemplateRefreshTimeout<br> =C2=A0 =C2=A0parameters as defined in [RFC6728].=C2=A0 Default = settings for these<br> =C2=A0 =C2=A0values are deployment- and application-specific.<b= r> <br> For transports with reliable template lifetimes (TCP, SCTP), templates require no refresh, since template state remains synchronized between exporter and collector.<br> <br> Cheers,<br> <br> Brian<br> <div> <div class=3D"gmail-m_-6801902955678215617h5"><br> <br> > On 2 Oct 2017, at 09:37, Petr Velan <<a href=3D"mai= lto:[email protected]" target=3D"_blank">[email protected]</a>> wrote:<br> ><br> > Hello IPFIX masters,<br> ><br> > we are implementing an IPFIX collector and a question came up whether to support templateLifePacket configuration as specified in RFC 6728 (<a href=3D"https://= tools.ietf.org/html/rfc6728#section-4.5.2" rel=3D"noreferrer" target=3D"_bl= ank">https://tools.ietf.org/html/r<wbr>fc6728#section-4.5.2</a>). It seems, that the *LifePacket options are not mentioned anywhere else in the IPFIX related documents and that the IPFIX protocol specifies only time based timeout expiration. Therefore, my question is why the *LifePacket options are even present in the RFC 6728 and whether it is necessary to implement them for the collector (and exporter as well) to be compliant with the IPFIX standard.<br> ><br> > I think that the whole *LifePacket option came from NetFlow v9 where the informational RFC 3954 states that:<br= > >=C2=A0 =C2=A0 =C2=A0 =C2=A0On a regular basis, the Expo= rter MUST send all the Template<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0Records and Options Template= Records to refresh the Collector.<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0Template IDs have a limited = lifetime at the Collector and MUST be<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0periodically refreshed.=C2= =A0 Two approaches are taken to make sure<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0that Templates get refreshed= at the Collector:<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0* Every= N number of Export Packets.<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0* On a = time basis, so every N number of minutes.<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0Both options MUST be configu= rable by the user on the Exporter.<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0When one of these expiry con= ditions is met, the Exporter MUST send<br> >=C2=A0 =C2=A0 =C2=A0 =C2=A0the Template FlowSet and Opt= ions Template.<br> ><br> ><br> > If that is the case, should the IPFIX standard specify something similar as well? Otherwise, it would seem that removing the *LifePacket options from the RFC 6728 would prevent further confusion.<br> ><br> > Kind regards,<br> > Petr Velan<br> ><br> </div> </div> > ______________________________<wbr>_________________<br> > IPFIX mailing list<br> > <a href=3D"mailto:[email protected]" target=3D"_blank">IPFIX@= ietf.org</a><br> > <a href=3D"https://www.ietf.org/mailman/listinfo/ipfix" re= l=3D"noreferrer" target=3D"_blank">https://www.ietf.org/mailman/l<wbr>istin= fo/ipfix</a><br> <br> </blockquote> </div> <br> </div> <br> <fieldset class=3D"gmail-m_-6801902955678215617mimeAttachmentHeader">= </fieldset> <br> <pre>______________________________<wbr>_________________ IPFIX mailing list <a class=3D"gmail-m_-6801902955678215617moz-txt-link-abbreviated" href=3D"m= ailto:[email protected]" target=3D"_blank">[email protected]</a> <a class=3D"gmail-m_-6801902955678215617moz-txt-link-freetext" href=3D"http= s://www.ietf.org/mailman/listinfo/ipfix" target=3D"_blank">https://www.ietf= .org/mailman/<wbr>listinfo/ipfix</a> </pre> </blockquote> <br> </div></div></div> </blockquote></div><br></div></div></div></div> --94eb2c0e71fca8fb96055a904a33-- --===============1939123794526503692== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ IPFIX mailing list [email protected] https://www.ietf.org/mailman/listinfo/ipfix --===============1939123794526503692==--