Re: [mpls] FW: I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt

[Loa Andersson <[e-mail]>]

Shraddha,

I made a mistake when I started the MPLS-RT review of this document.

I forgot add myself as Shepherd. Consequently I have not received the 
normal pings and also dropped a number of mails.

Going back over the over the mail archives I see that the authors are 
ready for WGAP.

I do not have a clear statement from the reviewers that they think the 
document is ready. Per above I might have missed some crucial mails.

Huub, Greg and Mach,

Can you confirm that your comments has been sufficiently addressed, and 
that we can go to WGAP?

/Loa

On 19/10/2021 06:50, Shraddha Hegde wrote:
> Chairs,
> 
> Authors believe all comments raised in MPLS-RT review have been 
> addressed and draft-ninan-mpls-spring-inter-domain-oam-04 draft is ready 
> for adoption call.
> 
> Request chairs to proceed with next step.
> 
> Rgds
> 
> Shraddha
> 
> Juniper Business Use Only
> 
> *From:* Greg Mirsky <[e-mail]>
> *Sent:* Wednesday, September 29, 2021 8:13 AM
> *To:* Shraddha Hegde <[e-mail]>
> *Cc:* [e-mail]; Mach Chen <[e-mail]>; 
> [e-mail]; [e-mail]; [e-mail]
> *Subject:* Re: [mpls] I-D Action: 
> draft-ninan-mpls-spring-inter-domain-oam-03.txt
> 
> *[External Email. Be cautious of content]*
> 
> Hi Shraddha,
> 
> I appreciate the work you and other authors put into addressing my 
> comments. I think that some of them can be discussed at a later time. At 
> this time I support the WG AP on draft-ninan-mpls-spring-inter-domain-oam.
> 
> Regards,
> 
> Greg
> 
> On Tue, Sep 28, 2021 at 10:09 AM Shraddha Hegde 
> <shraddha=[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
>     Dear MPLS-RT reviewers,
> 
>     I believe draft-ninan-mpls-spring-inter-domain-oam-04 addressed all
>     the comments received so far.
> 
>     Are there any more comments you would like to be addressed before
>     starting adoption call?
> 
>     Rgds
> 
>     Shraddha
> 
>     Juniper Business Use Only
> 
>     *From:* [e-mail] <mailto:[e-mail]>
>     <[e-mail] <mailto:[e-mail]>>
>     *Sent:* Sunday, July 25, 2021 8:18 AM
>     *To:* Shraddha Hegde <[e-mail]
>     <mailto:[e-mail]>>
>     *Cc:* [e-mail] <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>
>     *Subject:* Re:[mpls] I-D Action:
>     draft-ninan-mpls-spring-inter-domain-oam-03.txt
> 
>     *[External Email. Be cautious of content]*
> 
>     Hi Shraddha,
> 
>     thank you for your work addressing my comments and clarifying
>     questions I had.
> 
>     I believe that RFC 7743 is not saying what you think it is saying,
>     i.e., that the processing at a relay node must involve a particular
>     part of the system. I believe that that is an implementation detail
>     left out of RFC 7743. That is why I don't see that the proposed
>     mechanism has a sufficient advantage compared to RFC 7743. At the
>     same time, draft-ninan-mpls-spring-inter-domain-oam defines the
>     traceroute operation, which is left outside the scope in RFC 7743.
>     Perhaps that is the benefit, sufficient advancement for the MPLS WG
>     to adopt and work on the newly proposed mechanism?
> 
>     Regards,
> 
>     Greg Mirsky
> 
>     Sr. Standardization Expert
>     预研标准部/有线研究院/有线产品经营部Standard Preresearch
>     Dept./Wireline Product R&D Institute/Wireline Product Operation Division
> 
>     	
> 
> 
>     E: [e-mail] <mailto:[e-mail]>
>     www.zte.com.cn
>     <https://urldefense.com/v3/__http:/www.zte.com.cn/__;!!NEt6yMaO-gk!S-ilgxGLQvsXoVQRq-MuYNFsLCpiqAn178MUHnRC5y477BnUsVWA_oSonGwxLJX7$>
> 
>     Original Mail
> 
>     *Sender: *ShraddhaHegde
> 
>     *To: *gregory mirsky10211915;
> 
>     *CC: *[e-mail];[e-mail]
>     <mailto:[e-mail];[e-mail]> ;[e-mail]
>     <mailto:[e-mail]>;[e-mail]
>     <mailto:[e-mail]>;[e-mail]
>     <mailto:[e-mail]>;
> 
>     *Date: *2021/07/12 05:21
> 
>     *Subject: RE: Re:[mpls] I-D Action:
>     draft-ninan-mpls-spring-inter-domain-oam-03.txt*
> 
>     Hi Greg,
> 
>     Thanks for your comments.
> 
>     Snipped...
> 
>     GIM>> I see that the new text again characterizes RFC 7743 as requiring that an ASBR passes an echo reply to the control plane. Firstly, taking a packet out of the fast path processing does not automatically mean that it is punted to the control plane (what is the control plane of a networking system?). Also, the new text suggests that the mechanism described in the draft "simplifies operations to a greater extent in SR networks". It is not clear how that is achieved. Is that the result of transporting an echo reply over the MPLS data plane rather than, as defined in RFC 7743, IP network? If that is what you see as the advantage, could you please expand on why and in which case transporting the echo reply through MPLS simplifies operations in a multi-domain SR network?
>     <Shraddha> In terms of simplified operations what I meant was any MPLS capable node can be used in return path and not necessarily an echo-reply relay capable node.
>     If every node is echo-reply relay capable, there is no big advantage for operations. I agree with that. I have removed that sentence and also modified the statement regarding control plane.
>     Pls check the latest version and let me know if it looks good now.
> 
>     GIM>> As I've noted earlier, it is not clear how ASBR responds if the local policy prohibits it from participating in the described traceroute mode.
>     <Shraddha> That’s a good point. I have added this scenario and introduced a new return code in the reply path TLV to indicate this. Basically if ASBR's local
>     Policy does not allow it to send return path TLV, traceroute procedure for dynamic path building will encounter error and other means such as static
>     Return path through supporting ASBR need to be used by the operator.
> 
> 
>     GIM>> I think that the new text requires thorough analysis of how the Downstream Detailed Mapping TLV is handled by the remote domain. You would agree that exposing the inner topology to an external system poses a severe security risk.
>     <Shraddha> The procedures in this document are expected to be used across multiple domains that are under same administration or closely co-operating administration.
> 
>                              Exposing internal domain details to a legitimate source is not a problem but these procedures can be used by an attacker to get internal
>     Domain information which is a security risk. I have updated security consideration section and pointed to RFC 4379 that proposes possible security mechanisms.
> 
>     Yes I agree that there is scope for more discussion on this topic and probably more comprehensive security measures to be added.
>     Have posted latest revision and attached the diff here in this thread.
> 
> 
>     Rgds
>     Shraddha
> 
> 
> 
>     Juniper Business Use Only
> 
>     -----Original Message-----
>     From: [e-mail]
>     <mailto:[e-mail]> <[e-mail]
>     <mailto:[e-mail]>>
>     Sent: Tuesday, June 22, 2021 7:21 AM
>     To: Shraddha Hegde <[e-mail] <mailto:[e-mail]>>
>     Cc: [e-mail] <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>
>     Subject: Re:[mpls] I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt
> 
>     [External Email. Be cautious of content]
> 
> 
>     Hi Shraddha,
>     thank you for helping me with detailed clarifications. (Apologies for using plain text mode but we've noticed a problem our mailer exposes in the mailarchive). Please find my follow-up notes in-lined under GIM>> tag.
> 
>     Regards,
>     Greg Mirsky
>     Sr. Standardization Expert
>     预研标准部/有线研究院/有线产品经营部  Standard Preresearch Dept.
>     /Wireline Product R&D Institute/Wireline Product Operation Division
>     E: [e-mail] <mailto:[e-mail]>
>     www.zte.com.cn
>     <https://urldefense.com/v3/__http:/www.zte.com.cn__;!!NEt6yMaO-gk!V5MV0a785OzuCBbf-lgU7LxtncroCaUmnJp_c2F6Unh-AmeTC4mM6j5vqvPswGuT$>
>     ------------------Original Mail------------------
>     Sender: ShraddhaHegde
>     To: gregory mirsky10211915;
>     CC: [e-mail];[e-mail]
>     <mailto:[e-mail];[e-mail]> ;[e-mail]
>     <mailto:[e-mail]>;[e-mail]
>     <mailto:[e-mail]>;[e-mail]
>     <mailto:[e-mail]>;
>     Date: 2021/06/14 22:25
>     Subject: RE: Re:[mpls] I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt
>     v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);}" _ue_custom_node_="true"> Hi Greg, Thank you for the follow-up.
>     Pls see inline for replies.
>     -----Original Message-----
>     From: [e-mail]
>     <mailto:[e-mail]> <[e-mail]
>     <mailto:[e-mail]>>
>     Sent: Monday, June 14, 2021 5:50 AM
>     To: Shraddha Hegde <[e-mail] <mailto:[e-mail]>>
>     Cc: [e-mail] <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>; [e-mail]
>     <mailto:[e-mail]>
>     Subject: Re:[mpls] I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt
>     [External Email. Be cautious of content] Hi Shraddha and Authors, thank you for updating the draft. I've reviewed the new version and couldn't find most of my comments addressed. Could you kindly help by pointing to the specific changes in the draft that, in your opinion, address my comments @
>     https://urldefense.com/v3/__https://mailarchive.ietf.org/arch/msg/mpls/wmd0wbToaCEtDhgd2gFcX2HzG90/__;!!NEt6yMaO-gk!Rw6JdmD9WO__g0GzLwDiRtgamBQBekpwXb-QKJzwwfZB14cHNoFoYk7utpZBQaKX$
>     <https://urldefense.com/v3/__https:/mailarchive.ietf.org/arch/msg/mpls/wmd0wbToaCEtDhgd2gFcX2HzG90/__;!!NEt6yMaO-gk!Rw6JdmD9WO__g0GzLwDiRtgamBQBekpwXb-QKJzwwfZB14cHNoFoYk7utpZBQaKX$>  ?
>     <Shraddha>
>     Comment: I couldn't find a sufficient technical explanation for introducing a new mechanism for the inter-domain ping/traceroute in addition to the one described Addressed in section: 1 Introduction
>     Diff:
>     GIM>> I see that the new text again characterizes RFC 7743 as requiring that an ASBR passes an echo reply to the control plane. Firstly, taking a packet out of the fast path processing does not automatically mean that it is punted to the control plane (what is the control plane of a networking system?). Also, the new text suggests that the mechanism described in the draft "simplifies operations to a greater extent in SR networks". It is not clear how that is achieved. Is that the result of transporting an echo reply over the MPLS data plane rather than, as defined in RFC 7743, IP network? If that is what you see as the advantage, could you please expand on why and in which case transporting the echo reply through MPLS simplifies operations in a multi-domain SR network?
>     Comment: Three types of SID sub-TLVs are defined, but only use of one is mentioned in the document.
>     Addressed in section: 8
>     Diff:
>     Comment: I couldn't find an explanation of the relationship between IPv4/IPv6 Node Address and SID in Type 3 and Type 4 sub-TLVs, respectively
>     §            Also, in which scenario the SID field in Type 3 and Type 4 sub-TLVs is recommended?
>     Addressed in section: I would recommend reading  sections 6, 7 and 8 to get the complete description of how Type 3 and type 4 can be used.
>     Diff:
>     GIM>> The new text suggests that a local policy controls whether an ASBR cooperates with the described traceroute mode. I can assume that the policy would, for security reasons, prevent ASBR from participating. I couldn't find an explanation in the draft of what happens in that case.
>     Comment: And further, traceroute mode is called out of the scope of RFC 7743. I've read the explanation of traceroute in the draft, and I don't think it is a work Addressed in section: section 7.2
>     Diff:
>     As I've noted, I am not sure what is referred to as "the control plane" in the draft in describing the solution defined in RFC 7743. RFC 7743 itself does not, as I understand it, require that an Echo Reply is sent to the control plane  at any step.
>     <shraddha> RFC 7743 describes how to relay the echo-reply in section 4.4.
>     The relaying node receives the echo-reply packet with destination set to relay node. Then the relaying node need To examine the "Relay Node Address stack TLV" to find the next relay node or the initiator and send either relayed- Echo-reply or a normal echo-reply based on whether there are further relay nodes to be visited.
>     My understanding is that this complex operation of finding the next relay node from the packet and replacing That into the destination address of the packet would require packet to be sent to control plane and cannot be done in forwarding plane.
>     GIM>> I think that when some processing is done outside of the fast path that is not necessarily means that that function must be completed in the control plane (which is still not clear what the "control plane" means in the context of this draft). I can imagine that that extra processing is done as bump-in-a-wire as the rate of echo replies is controlled.
> 
>       Also relay node receives the packet with destination address set to the relay node. The normal behaviour  of a router for self addressed packets is to send the packet to control plane, the draft does not talk about
>     GIM>> Though that might be the case, implementations are using special cases to optimize some scenarios.
> 
>     Any forwarding plane behaviour change with respect to self destined packets.
>     If you have an implementation that does that, perhaps we can look at whether that is indeed the property of the solution or is implementation-specific.
>     <shraddha> I would like to understand if you have an implementation where the  relayed echo-reply processing on the relay node is done in forwarding plane. The RFC does not specify explicitly that  relay node processing is to  be done in forwarding plane also does not Provide enough details that would be needed to process the "relay node address stack TLV"  in forwarding plane.
>     Also, I'm still concern with the specification for traceroute mode in the draft. I have a couple of additional notes to add:
>     - RFC 7110, as well as RFC 7743 (I've pointed that out in my first comments), has traceroute outside the scope; <Shraddha> This draft has addressed traceroute and provided enough details on how traceroute procedure Works. Let me know if you have specific questions on traceroute procedure.
>     GIM>> As I've noted earlier, it is not clear how ASBR responds if the local policy prohibits it from participating in the described traceroute mode.
> 
>     Do you have a concern with this draft addressing traceroute? As long as this draft provides a workable Solution it should not matter whether previous RFCs in the area addressed traceroute or not!
>     - RFC 8029 (Section 4.3) recommends using the Downstream Detailed Mapping TLV. I couldn't find that TLV being mentioned in the draft. If you believe that TLV must not be used, could you list reasons for not using the Downstream Detailed  Mapping TLV?
>     <Shraddha> Downstream Detailed Mapping TLV is very much used.
>     Section 6.2 specifies no changes to RFC 8029/RFC 8287 procedures.
>     The change is only in processing additional reply path TLV when it comes in echo-request And also in adding this Return path TLV while sending echo-reply.
>     " The responder MUST follow the normal FEC validation procedures as described in [RFC8029] and [RFC8287] and this document does not suggest any change to those procedures."
> 
>     If  it is not clear enough, I can update the text as below " The responder MUST follow the normal FEC validation procedures and echo-reply building procedures as  described in [RFC8029] and [RFC8287] and this document does not suggest any change to those procedures."
> 
>     Let me know if that works for you.
>     GIM>> I think that the new text requires thorough analysis of how the Downstream Detailed Mapping TLV is handled by the remote domain. You would agree that exposing the inner topology to an external system poses a severe security risk.
>     Regards,
>     Greg Mirsky
>     Sr. Standardization Expert
>     预研标准部/有线研究院/有线产品经营部   Standard Preresearch Dept.
>     /Wireline Product R&D Institute/Wireline Product Operation Division
>     E: [e-mail] <mailto:[e-mail]>
>     www.zte.com.cn
>     <https://urldefense.com/v3/__http:/www.zte.com.cn__;!!NEt6yMaO-gk!V5MV0a785OzuCBbf-lgU7LxtncroCaUmnJp_c2F6Unh-AmeTC4mM6j5vqvPswGuT$>
>     ------------------Original Mail------------------
>     Sender: ShraddhaHegde
>     To: [e-mail];[e-mail]
>     <mailto:[e-mail];[e-mail]> ;Mach Chen;gregory
>     mirsky10211915;[e-mail]
>     <mailto:[e-mail]>;[e-mail]
>     <mailto:[e-mail]>;
>     Date: 2021/06/11 01:34
>     Subject: RE: [mpls] I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt
>     Hi All,
>     New version of draft-ninan-mpls-spring-inter-domain-oam is posted addressing comments from MPLS-RT review.
>     Pls take a look and let me know if you have further comments.
>     Rgds
>     Shraddha
>     Juniper Business Use Only
>     -----Original Message-----
>     From: mpls  On Behalf Of [e-mail]
>     <mailto:[e-mail]>
>     Sent: Friday, June 11, 2021 2:00 PM
>     To: [e-mail] <mailto:[e-mail]>
>     Cc: [e-mail] <mailto:[e-mail]>
>     Subject: [mpls] I-D Action: draft-ninan-mpls-spring-inter-domain-oam-03.txt
>     [External Email. Be cautious of content] A New Internet-Draft is available from the on-line Internet-Drafts directories.
>     This draft is a work item of the Multiprotocol Label Switching WG of the IETF.
>     Title           : PMS/Head-end based MPLS Ping and Traceroute in Inter-domain SR Networks
>     Authors         : Shraddha Hegde
>     Kapil Arora
>     Mukul Srivastava
>     Samson Ninan
>     Nagendra Kumar
>     Filename        : draft-ninan-mpls-spring-inter-domain-oam-03.txt
>     Pages           : 21
>     Date            : 2021-06-11
>     Abstract:
>     Segment Routing (SR) architecture leverages source routing and tunneling paradigms and can be directly applied to the use of a Multiprotocol Label Switching (MPLS) data plane.  A network may consist of multiple IGP domains or multiple  ASes under the control of same organization.  It is useful to have the LSP Ping and traceroute procedures when an SR end-to-end path spans across multiple ASes or domains.  This document describes mechanisms to facilitae LSP ping and traceroute in inter-AS/inter-domain  SR networks in an efficient manner with simple OAM protocol extension which uses dataplane forwarding alone for sending echo reply.
>     The IETF datatracker status page for this draft is:
>     https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ninan-mpls-spring-inter-domain-oam/__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5TuJNnI5%7B0%7Dlt;br
>     <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-ninan-mpls-spring-inter-domain-oam/__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5TuJNnI5%7B0%7Dlt;br>>
> 
>     There is also an htmlized version available at:
>     https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draft-ninan-mpls-spring-inter-domain-oam-03__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5VMFXpJm%7B0%7Dlt;br
>     <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/html/draft-ninan-mpls-spring-inter-domain-oam-03__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5VMFXpJm%7B0%7Dlt;br>>
> 
>     A diff from the previous version is available at:
>     https://urldefense.com/v3/__https://www.ietf.org/rfcdiff?url2=draft-ninan-mpls-spring-inter-domain-oam-03__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5QEnIeV0%7B0%7Dlt;br
>     <https://urldefense.com/v3/__https:/www.ietf.org/rfcdiff?url2=draft-ninan-mpls-spring-inter-domain-oam-03__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5QEnIeV0%7B0%7Dlt;br>>
> 
>     Internet-Drafts are also available by anonymous FTP at:
>     https://urldefense.com/v3/__ftp://ftp.ietf.org/internet-drafts/__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5T0hqLuk%7B0%7Dlt;br
>     <https://urldefense.com/v3/__ftp:/ftp.ietf.org/internet-drafts/__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5T0hqLuk%7B0%7Dlt;br>>
> 
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>     https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/mpls__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5TdmWWCx%7B0%7Dlt;br
>     <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/mpls__;!!NEt6yMaO-gk!WjDBRkDAvnDKCC6tb3iz7_nNl8kTHr2mV0bTh80i0AzKeABzFQV3dfGS5TdmWWCx%7B0%7Dlt;br>>
> 
> 
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Loa Andersson                        email: [e-mail]
Senior MPLS Expert                          [e-mail]
Bronze Dragon Consulting             phone: [phone]