Re: [Gen-art] Genart last call review of draft-ietf-idr-bgp-open-policy-18

[Gyan Mishra <[e-mail]>]

Hi Sriram & Alexander

Responses in-line

Kind Regards

On Tue, Jan 4, 2022 at 11:35 AM Sriram, Kotikalapudi (Fed) <
[e-mail]> wrote:

> Hi Gyan,
>
> [I am following up on the messages exchanged between Alvaro and you this
> morning. Thanks to both of you for that.]
>
> Sorry for the delay in replying (considering your original review date).
> Thank you for your careful review and comments/nits. Please see responses
> marked with [KS/AA] below.
>
> > Comment related to Gao-Rexford model.  The Gao-Rexford Model only has 3
> peer
> types North bound upstream Provider, Southbound Customer and lateral same
> tier
> level peer.  With the role capabilities, RS and RS-Client is added which
> makes
> it slightly different but almost identical.  In describing the role types
> would
> it make sense to have a graphical depiction of Gao-Redford model with the
> role
> capabilities on adjacent peers to help explain the role relationship for
> local
> and remote-as.  Just an idea to help explain the role capabilities.
>
> [KS/AA]: We felt that instead of a graphical depiction, it is more useful
> to include text to enumerate the peering relationships corresponding to
> various Roles. So, we have added (in v-19 to be uploaded soon that will
> also include changes to reflect Ines' comments) the following new text in
> Section 2 after Roles are defined:


   Gyan> Perfect

>
>    If the local AS has one of the above Roles (in the order shown), then
>    the corresponding peering relationship with the remote AS is
>    Provider-to-Customer, Customer-to-Provider, RS-to-RS-Client, RS-
>    Client-to-RS, or Peer-to-Peer (i.e., lateral peers), respectively.


>
> Please let us know if this seems acceptable.


Gya> Agreed that is acceptable.  In the description as well maybe listing a
pecking order similar to what is described in Gao-Rexford model style
 route preference in the import and export policy verbiage for each role.
Also could mention that a good reasons for role capabilities usage by
operators  is to prevent routing policy disputes between peering points
that can result in sub optimal routing instability and feedback loops along
with route leaks mentioned.

>
>
> >In the role correctness section scenario where the peer receives multiple
> role
> capabilities to send role mismatch notification.  What if there is a timing
> issue and the multiple are received after the BGP open and peer is
> established
> possible sequence of events issue.  Is it possible the peer may not get a
> mismatch notification if the peer establishes prior to getting a different
> capabilities where a mismatch or problem exists that is missed that could
> result in a route leak. I am thinking of possibly false positive or
> negative or
> negative during BGP open  capabilities exchange.
>
> [KS/AA]: We feel that Alvaro has already adequately addressed this comment
> in his two messages. Please let us know if you still have a question.


    Gyan> Agreed.

>
> Regards,
> Sriram / Alexander
>
> -----------------------------------------------------------------------
> From: Gyan Mishra <[e-mail]>
> Sent: Tuesday, January 4, 2022 10:44 AM
> To: Alvaro Retana <[e-mail]>
> Cc: Gyan Mishra via Datatracker <[e-mail]>;
> [e-mail]; [e-mail];
> [e-mail]; [e-mail]
> Subject: Re: Genart last call review of draft-ietf-idr-bgp-open-policy-18
>
> Hi Alvaro
>
> Happy New Year!
>
> Welcome!
>
> On Tue, Jan 4, 2022 at 10:12 AM Alvaro Retana <[e-mail]>
> wrote:
>
> > On December 21, 2021 at 8:01:21 PM, Gyan Mishra wrote:
> >
> > Gyan:
> >
> > Hi!  Happy New Year!
> >
> > Thank you for the review!
> >
> >
> > ...
> > > Summary: ... The new BGP role capabilities mismatch code 2 subcode 8
> > > discussed on ML seems to have multiple implementations deployed and one
> > > confined by Cisco. I agree that the authors should request a new
> subcode
> > > for the role mismatch notification.
> >
> > To catch others up:  there is a confirmed case of squatting on the
> > assigned subcode.  A consultation on the next steps is open on the idr
> > list and will close tomorrow (Jan/5).
> >
> > https://mailarchive.ietf.org/arch/msg/idr/RBD3Z9YIboudGAIeJLS8L--p4BU/
> >
> > Gyan> Thanks for update
> > ...
> > > Nits/editorial comments:
> > > Comment related to Gao-Rexford model. The Gao-Rexford Model only has 3
> > peer
> > > types North bound upstream Provider, Southbound Customer and lateral
> same
> > > tier level peer. With the role capabilities, RS and RS-Client is added
> > which
> > > makes it slightly different but almost identical. In describing the
> role
> > > types would it make sense to have a graphical depiction of Gao-Redford
> > model
> > > with the role capabilities on adjacent peers to help explain the role
> > > relationship for local and remote-as. Just an idea to help explain the
> > role
> > > capabilities.
> >
> > The role definitions are described in this document, not strictly
> > carried over from Gao-Rexford.  Nonetheless, a graphical description
> > on the roles defined here may make sense.  I'll leave it to the
> > authors to consider (if not too complicated).
>
>
> Gyan> Perfect
>
> >
> >
> >
> > > In the role correctness section scenario where the peer receives
> multiple
> > > role capabilities to send role mismatch notification. What if there is
> a
> > > timing issue and the multiple are received after the BGP open and peer
> is
> > > established possible sequence of events issue. Is it possible the peer
> > may
> > > not get a mismatch notification if the peer establishes prior to
> getting
> > a
> > > different capabilities where a mismatch or problem exists that is
> missed
> > > that could result in a route leak. I am thinking of possibly false
> > positive
> > > or negative or negative during BGP open capabilities exchange
> >
> > All capabilities are signaled in the OPEN, so there's no possibility
> > for receiving a Role Capability afterwards.
> >
>
> Gyan> Agreed.  The multiple capabilities received is mentioned in the text,
> however as it's signaled in the open how would multiple capabilities be
> received.  As the role capabilities are sent in the open , how can the
> possibility of multiple capabilities occur?
>
> >
> >
> > Alvaro.
> >
> --
>
> <http://www.verizon.com/>
>
> *Gyan Mishra*
>
> *Network Solutions A**rchitect *
>
> *Email [e-mail] <[e-mail]>*
>
>
>
> *M 301 502-1347*
>
-- 

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *

*Email [e-mail] <[e-mail]>*



*M 301 502-1347*