Re: [spring] draft-filsfils-spring-net-pgm-extension-srv6-usid-07

["Pablo Camarillo (pcamaril)" <[e-mail]>]

Hi Rajesh,

Inline [PC].

Thanks.

From: spring <[e-mail]> On Behalf Of Rajesh M
Sent: jueves, 10 de septiembre de 2020 12:45
To: Peter Psenak <ppsenak=[e-mail]>; SPRING WG <[e-mail]>
Subject: Re: [spring] draft-filsfils-spring-net-pgm-extension-srv6-usid-07

Hi peter,

1)  What is the difference between these 2 SIDs
42 | 0x002A | uN | [This.ID] |
46 | 0x002E | uN (S&L+End PSP/USP) | [This.ID] |

uN SID (End behavior with NEXT-CSID, PSP and USD flavors) ,  uN (S&L+End PSP/USD)
[PC] This is a typo. The example in 4.1.1 needs to be corrected to use | 48    | 0x0030 |    uN (S&L+End PSP/USD)    | [This.ID] |

2)  just to continue below discussion, can you confirm
51 | 0x0033 | uA                              - here FIB must have 2001:db8:0:FNAJ::/64 route (16 bit Compressed-SID)
52 | 0x0034 | uA (S&X+End.X)     -  here FIB must have 2001:db8:0:0N00:FNAJ::/80 route (32 bit Compressed-SID)

[PC] Not the case. The FIB entry must have 2001:db8:0:FNAJ::/64. This is independent on which flavor the node supports 51-59.
Note that it may also be possible for a packet to arrive to the node with uN uSID followed by a uA.
In such case the packet arriving at the node is 2001:db8:0:0N00:FNAJ::, whereas 0N00 is a uN at node N, and FNAJ is a uA at node N toward neighbor J
I can add a note about this in the next revision of the draft.

Thanks
Rajesh


-----Original Message-----
From: Peter Psenak <ppsenak=[e-mail]<mailto:ppsenak=[e-mail]>>
Sent: Thursday, September 10, 2020 3:36 PM
To: Rajesh M <[e-mail]<mailto:[e-mail]>>; SPRING WG <[e-mail]<mailto:[e-mail]>>
Subject: Re: [spring] draft-filsfils-spring-net-pgm-extension-srv6-usid-07

[External Email. Be cautious of content]


Hi Rajesh,

On 10/09/2020 03:38, Rajesh M wrote:
> Hi All,
>
> *Section 4.1.21:*
>
> **
>
> In control plane uA SID is advertised with value
> 2001:db8:0:*0N00:FNAJ::*
>
> **
>
> *in FIB entry it is represent with value *2001:db8:0*:FNAJ::/64*
>
> Note: From a formal viewpoint, a uA SID of node N is defined by the
>
> local FIB entry B:uA/64 of N (i.e. this definition is independent from
> any uN SID of node N).
>
> a) why such discrepancy ? between control plane and forwarding plane.

It's explained in the section 4.1.2.1:

"In order to signal in ISIS a container SID with the same routable semantics as End.X"

In other words, we wanted to keep the consistency in a way the SID is advertised for different SID types (e.g. END.X and uA).

thanks,
Peter


>
> b) for uA SID Forwarding happens based upon 2001:db8:0/48 ? not based
> upon 2001:db8:0:*0N00 (uN SID) ?*
>
> **uSID block: 2001:db8:0::/48**
>
> **for uA SID if forwarding is based upon**2001:db8:0/48 then
> Compressed-SID can be 16 bit
>
>     for uA SID if forwarding is based upon**2001:db8:0:*0N00 then
> *Compressed-SID must be 32 bit**
>
> **
>
> Thanks
>
> Rajesh
>
> **
>
>
> Juniper Business Use Only
>


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