Re: Request for comments: draft-jain-nvo3-overlay-oam-01.txt

[Anil Lohiya <[e-mail]>]

Shahram,

BFD can not replace the functionality provided by the overlay oam mechanism e.g. bfd can't provide the functions such as control and data plane validation, ECMP path discovery, traceroute etc.

regarding including vni, vsid etc. in TLV – control and data plane maybe out of sync due to different reasons and we can not assume that the VNI in the outer header is what user intended to validate against in its echo request. So, adding VNI explicitly in the TLV makes sure that egress is really validating what the user intended it to.

thanks
- Anil

From: Shahram Davari <[e-mail]<mailto:[e-mail]>>
Date: Thursday, February 27, 2014 11:19 AM
To: Anil Lohiya <[e-mail]<mailto:[e-mail]>>, Thomas Nadeau <[e-mail]<mailto:[e-mail]>>, "Henderickx, Wim (Wim)" <[e-mail]<mailto:[e-mail]>>
Cc: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, Pradeep Jain <[e-mail]<mailto:[e-mail]>>, Vinay Bannai <[e-mail]<mailto:[e-mail]>>, Ravi Shekhar <[e-mail]<mailto:[e-mail]>>
Subject: RE: Request for comments: draft-jain-nvo3-overlay-oam-01.txt

Anil,

I don’t agree. If you use for example BFD for inner IP, and if BFD says connectivity is OK, this implies that the Overlay connectivity is also OK, since BFD is inside the overlay.
Also I am not sure why you are adding the VNI, VSID, etc in the message as TLV, since these value are already in the packet header.

Thx
Shahram

From: L2vpn [mailto:[e-mail]] On Behalf Of Anil Lohiya
Sent: Thursday, February 27, 2014 10:19 AM
To: Thomas Nadeau; Henderickx, Wim (Wim)
Cc: [e-mail]<mailto:[e-mail]>; Pradeep Jain; Vinay Bannai; Ravi Shekhar
Subject: Re: Request for comments: draft-jain-nvo3-overlay-oam-01.txt


Existing ping/traceroute mechanisms don't work in the virtualized environment e.g. ping may report that IP reachability between the ingress and egress tunnel endpoints is fine but the end systems (i.e. VM, physical server etc.) connectivity for a tenant could still be broken. This is because ping only verifies basic connectivity between two endpoints in the underlay but NOT in the context of overlay segments. Hence, we need debugging tools that work in the overlay environment. Think why there was a need to have lsp ping … requirement with IP overlays is not much different.

Question is not whether applications are resilient or not… One can not ignore the fact that operators have to think about having the right tools when that "inevitable" call  comes from their customer about deteriorating application performance or traffic blackhole and there are no tools today specific to overlay network debugging.

- Anil

From: Thomas Nadeau <[e-mail]<mailto:[e-mail]>>
Date: Thursday, February 27, 2014 8:05 AM
To: "Henderickx, Wim (Wim)" <[e-mail]<mailto:[e-mail]>>
Cc: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, Pradeep Jain <[e-mail]<mailto:[e-mail]>>, Vinay Bannai <[e-mail]<mailto:[e-mail]>>, Ravi Shekhar <[e-mail]<mailto:[e-mail]>>
Subject: Re: Request for comments: draft-jain-nvo3-overlay-oam-01.txt


The question is, and perhaps the draft could explain this, is why existing tools a) are insufficient and b) cannot be modified.
Operationally speaking, b is preferred if you ask me as learning a new tool/model for diagnosis and trouble-shooting is expensive and painful.
For example, if we took the tact of reinventing say IP ping for every underlying transport, then we'd have 50 tools by now.

--Tom



On Feb 27, 2014:11:02 AM, at 11:02 AM, Henderickx, Wim (Wim) <[e-mail]<mailto:[e-mail]>> wrote:


Because we also need to trace L2 endpoints besides IP endpoint.

From: Shahram Davari <[e-mail]<mailto:[e-mail]>>
Date: Thursday 27 February 2014 16:58
To: Kanwar Singh <[e-mail]<mailto:[e-mail]>>
Cc: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, Pradeep Jain <[e-mail]<mailto:[e-mail]>>, Vinay Bannai <[e-mail]<mailto:[e-mail]>>, Ravi Shekhar <[e-mail]<mailto:[e-mail]>>
Subject: Re: Request for comments: draft-jain-nvo3-overlay-oam-01.txt

Hi

Why don't you use existing IP based OAM messages such as BFD, OWAMP, TWAMP, etc.

Regards,
Shahram


On Feb 27, 2014, at 7:46 AM, "Kanwar Singh" <[e-mail]<mailto:[e-mail]>> wrote:
Dear All,

We have submitted the below draft that proposes Generic OAM and Datapath Failure Detection Mechanism(s) for Overlay Networks.

We would like to solicit inputs from the members of L2VPN WG.

Please review the same and update us with your inputs/feedback.


Warm Regards

- Kanwar





A new version of I-D, draft-jain-nvo3-overlay-oam-01.txt has been successfully submitted by Kanwar Singh and posted to the

IETF repository.

Name:           draft-jain-nvo3-overlay-oam
Revision:       01
Title:          Generic Overlay OAM and Datapath Failure Detection
Document date:  2014-02-12
Group:          Individual Submission
Pages:          44
URL:            http://www.ietf.org/internet-drafts/draft-jain-nvo3-overlay-oam-01.txt
Status:         https://datatracker.ietf.org/doc/draft-jain-nvo3-overlay-oam/
Htmlized:      http://tools.ietf.org/html/draft-jain-nvo3-overlay-oam-01
Diff:              http://www.ietf.org/rfcdiff?url2=draft-jain-nvo3-overlay-oam-01

Abstract:
   This proposal describes a mechanism that can be used to detect Data
   Path Failures of various overlay technologies as VXLAN, NVGRE,
   MPLSoGRE and MPLSoUDP and verifying/sanity of their Control and Data
   Plane for given Overlay Segment.  This document defines the following
   for each of the above Overlay Technologies:

   o  Encapsulation of OAM Packet, such that it has same Outer and
      Overlay Header as any End-System's data going over the same
      Overlay Segment.

   o  The mechanism to trace the Underlay that is exercised by any
      Overlay Segment.

   o  Procedure to verify presence of any given Tenant VM or End-System
      within a given Overlay Segment at Overlay End-Point.

   Even though the present proposal addresses Overlay OAM for VXLAN,
   NVGRE, MPLSoGRE and MPLSoUDP, but the procedures described are
   generic enough to accommodate OAM for any other Overlay Technology.