[pim] Re: PIM vs. mLDP MT/FA

[Peter Psenak <[e-mail]>]

Hi Sandy,

On 25/07/2024 23:31, [e-mail] wrote:
>
> Hi Peter,
>
> Thank you for your explanation!
>
> The PIM is not binded to SR.
>
Flex-algo can compute path to:

1. SR-MPLS prefixes with algo specific label - SR-MPLS data-plane

2. SRv6 locators - SRv6 data-plane

3. IP algo prefixes - RFC 9502. - IP algo data-plane

In addition FA needs routers to announce participation in one of the 
specific data-planes from the above list.

> PIM needs the unicast next hop calculated by IGP in specific MT or FA 
> to the Source, but the label or SR locator isn't needed.
>
I'm afraid FA can not give you what you want at the moment. Maybe we can 
extend it to do so ...


> So whatever the Group is, PIM just lookup the IGP table to get the 
> next hop to the source.
>
it's not that simple with flex-algo :)

thanks,
Petetr

> PIM still can get what needed even if the Source is the same but the 
> Groups are different.
>
> Thanks,
>
> Sandy
>
>
> Original
> *From: *PeterPsenak <ppsenak=[e-mail]>
> *To: *Jeffrey (Zhaohui) Zhang <[e-mail]>;
> *Cc: *'[e-mail]' <[e-mail]>;
> *Date: *2024年07月25日 05:55
> *Subject: **[pim] Re: PIM vs. mLDP MT/FA*
> _______________________________________________
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> Hi Jeffrey ,
>
> On 24/07/2024 23:42, Jeffrey (Zhaohui) Zhang wrote:
>> Hi Peter,  Thanks for the reminder that in the case of mLDP and SRv6-P2MP the labels/locators can be tied to MT/FA. In the case of PIM, we need to clarify that an (s,g) tree will be tied to a particular MT/FA - not that there could be multiple per-MT/FA trees for the same (s,g).
>
> the point is that in  SRv6 there is only a single path to any locator, 
> which is in an algo to which the locator belongs. There could not be 
> any other algo path computed for it.
>
> Coming back to your case, the path would then be per source (assuming 
> it is covered by the locator) and can not be per (s,g). For different 
> algo you need a different source in SRv6.
>
> If you want to be able to have paths in different algo for the same 
> prefix, you can use SR-MPLS, or we would have to come up with 
> something new....
>
> thanks,
> Peter
>
>> Thanks.  Jeffrey  Juniper Business Use Only
>
>
>