Re: [spring] SR replication segment for P2MP MDT

[Gyan Mishra <[e-mail]>]

On Sun, Mar 22, 2020 at 4:45 PM Gyan Mishra <[e-mail]> wrote:

>
>
> On Sat, Mar 21, 2020 at 3:22 PM Rishabh Parekh <[e-mail]> wrote:
>
>> Gyan,
>>
>> >The SR replication segment tree sid draft states that it can only be
>> used for PCE centralized controller model.
>> >I am guessing BIER maybe an option?
>>
>> Strictly speaking, BIER is not SR dataplane, but yes it is an option.
>
>
>     So BIER technically can be used with SR but has its own BIFT
> forwarding table.  Understood.
>
> For the WG question I posed is that if LDP is eliminated from SP core and
> you don’t want to use RSVP-TE and BIER is not yet available and SR
> replication tree SID draft can only be used if a centralized PCE is
> utilized what alternatives or options does the operators have?
>
> Also if PCE is configured on SR source node in a hybrid model and BGP
> prefix SID is advertise by PCC elements in IGP via BGP LS propagation would
> that be an option for SR-MPLS multicast P2MP and MP2MP LMDTs?
>
>>
>>
>> Any other options for operators?
>>
>> LDP with RFC 7473 can be used just for mLDP LSPs.
>>
>
> So in the case where you have LDP still enabled in the core and have
> SR-PREFER configured so all L3 vpn unicast traffic is using SR-MPLS
> forwarding plane - so then for multicast to work to use mLDP data plane
> this draft and what you are saying for that to work is you have to
> configure a knob to disable FEC root prefix lsp.  Not sure how that would
> work as that mldp fec binding for mLDP core p-tree gloabal is PSMI/UI/MI/S
> MVPN instantiation of the tree how would that even work.
>
> There is some XR knob I am missing to get this working and is key for any
> mLDP MVPN profiles Verizon will be using.
>
>
>
> 6.4 <https://tools.ietf.org/html/rfc7473#section-6.4>.  Disabling Prefix-LSPs on an mLDP-only Session
>
>    Assume that LSR1 and LSR2 have formed an LDP session to exchange mLDP
>    state only.  In typical deployments, LSR1 and LSR2 also exchange
>    bindings for IP (unicast) prefixes upon mLDP session, which is
>    unnecessary and wasteful for an mLDP-only LSR.
>
>    Using the procedures defined earlier, an LSR can indicate its
>    disinterest in Prefix-LSP application state to its peer upon session
>    establishment time or dynamically later via an LDP capabilities
>    update.
>
>    In reference to Section 3.1 <https://tools.ietf.org/html/rfc7473#section-3.1>, the peer disables the advertisement of
>    any state related to IP Prefix FECs, but it still advertises IP
>    address bindings that are required for the correct operation of mLDP.
>
>
>   I found the RFC 7473 sac knob for SR for capability exchange for
> mldp-only and configured on PEs first still no change in MRIB state on
> egress PE
>


> then added knob to all Ps as well and still no change.  We can continue
> "off list". Thanks.
>

RP/0/RP0/CPU0:PE1-XRV9k#sh run mpls ldp
Sun Mar 22 23:12:24.127 UTC
mpls ldp
 !

*capabilities sac mldp-only *
>
> -Rishabh
>>
>> On Sat, Mar 21, 2020 at 11:11 AM Gyan Mishra <[e-mail]>
>> wrote:
>> >
>> >
>> > Thank you Rishabh!
>> >
>> > I will contact you regarding Cisco specific questions.
>> >
>> > The questions apply to multicast support with SR-MPLS and are not
>> vendor specific however I am using Cisco as an example.
>> >
>> > From a IETF standards perspective, I believe the one question that this
>> thread is related is with multicast  SR-MPLS support use case where you are
>> migrated to SR-MPLS and LDP has been removed from the SP core.
>> >
>> > In this customer use case where the customer does not want to use RSVP
>> TE or IR due to replication processing overhead in a distributed model what
>> options are available for multicast support.
>> >
>> > The SR replication segment tree sid draft states that it can only be
>> used for PCE centralized controller model.
>> >
>> > I am guessing BIER maybe an option?
>> >
>> > Any other options for operators?
>> >
>> > Kind regards
>> >
>> > Gyan
>> >
>> > On Sat, Mar 21, 2020 at 1:49 PM Rishabh Parekh <[e-mail]>
>> wrote:
>> >>
>> >> Gyan,
>> >> These questions are implementation specific and should be addressed
>> >> off the mailing list. Please contact me at [e-mail].
>> >>
>> >> -Rishabh
>> >>
>> >> On Fri, Mar 20, 2020 at 6:41 PM Gyan Mishra <[e-mail]>
>> wrote:
>> >> >
>> >> >
>> >> > Daniel & Authors
>> >> >
>> >> > I had a question related to the draft related to lab POC testing.
>> >> >
>> >> >
>> https://datatracker.ietf.org/doc/draft-voyer-spring-sr-replication-segment/
>> >> >
>> >> > In the draft it states that SR replication using Tree SID to
>> replication to leafs on a tree is only supported with a centralized PCE
>> controller based model using BGP LS.
>> >> >
>> >> > I have an SR-MPLS Cisco VIRL POC test bed using XRV9000 nodes 7.0.1
>> using ISIS SR extensions where I have L3 vpn overlay and everything is
>> working very well from a unicast perspective.  No issues.
>> >> >
>> >> > I have LDP still enabled but via “SR-Prefer” am using SR-MPLS
>> forwarding plane.  I kept LDP enabled so I can use mLDP for LMDT label
>> switched trees for multicast and technically that all MVPN procedures RFC
>> 6513 6514 encap tunnel types should work for p-tree using mLDP forwarding
>> plane for multicast while SR-MPLS is being used for unicast..
>> >> >
>> >> > I can get the LMDT core tree default and data mdt to build for MP2MP
>> or P2MP tree but cannot get on the FEC root the MRIB state to build.  Not
>> sure why?
>> >> >
>> >> > Any ideas.  Is there anything special I have to do for multicast to
>> use the ldp mLDP extension data plane and not the SR-MPLS data plane.
>> >> >
>> >> > I think what’s happening is at the data plane forwarding level
>> SR-MPLS data plane is being used instead of mLDP.
>> >> >
>> >> > I have a bunch of SR-TE policies in place with candidate dynamic and
>> static ERO paths and that works well coloring the VRF steering.
>> >> >
>> >> > I was wondering if I can use SR-TE binding Sid with Static ERO loose
>> path using prefix SID of egress PE to replicate to and build P2MP tree
>> instantiation via SR-TE.
>> >> >
>> >> > Is that possible?
>> >> >
>> >> > Kind regards
>> >> >
>> >> > Gyan
>> >> >
>> >> >
>> >> > --
>> >> >
>> >> > Gyan  Mishra
>> >> >
>> >> > Network Engineering & Technology
>> >> >
>> >> > Verizon
>> >> >
>> >> > Silver Spring, MD 20904
>> >> >
>> >> > Phone: [phone]
>> >> >
>> >> > Email: [e-mail]
>> >> >
>> >> >
>> >> >
>> >> > _______________________________________________
>> >> > spring mailing list
>> >> > [e-mail]
>> >> > https://www.ietf.org/mailman/listinfo/spring
>> >
>> > --
>> >
>> > Gyan  Mishra
>> >
>> > Network Engineering & Technology
>> >
>> > Verizon
>> >
>> > Silver Spring, MD 20904
>> >
>> > Phone: [phone]
>> >
>> > Email: [e-mail]
>> >
>> >
>> >
>>
> --
>
> Gyan  Mishra
>
> Network Engineering & Technology
>
> Verizon
>
> Silver Spring, MD 20904
>
> Phone: [phone]
>
> Email: [e-mail]
>
>
>
>

-- 

Gyan  Mishra

Network Engineering & Technology

Verizon

Silver Spring, MD 20904

Phone: [phone]

Email: [e-mail]