Hi Chris,
They are the same thing.
Section 3:
...
Its processing is defined in [I-D.ietf-6man-segment-routing-header]
section 4.3 and reproduced here as a reminder.
Without constraining the details of an implementation, the SR
segment endpoint node creates Forwarding Information Base (FIB)
entries for its local SIDs.
When an SRv6-capable node receives an IPv6 packet, it performs a
longest-prefix-match lookup on the packets destination address.
This lookup can return any of the following:
- A FIB entry that represents a locally instantiated SRv6 SID
- A FIB entry that represents a local interface, not locally
instantiated as an SRv6 SID
- A FIB entry that represents a non-local route
- No Match
Section 4:
> Each FIB entry indicates the behavior associated with a SID instance
> and its parameters.
Thank you,
Pablo.
-----Original Message-----
From: Christian Hopps <cho...@chopps.org>
Date: Tuesday, 10 March 2020 at 22:01
To: "Pablo Camarillo (pcamaril)" <pcama...@cisco.com>
Cc: Christian Hopps <cho...@chopps.org>, "spring@ietf.org" <spring@ietf.org>
Subject: Re: [spring] Question on draft-ietf-spring-srv6-network-programming-12
> On Mar 10, 2020, at 2:13 PM, Pablo Camarillo (pcamaril)
<pcamaril=40cisco....@dmarc.ietf.org> wrote:
>
> Hi Chris,
>
> Thanks for going through the document.
> The behaviors 4.13 (End.B6.Encaps), 4.14 (End.B6.Encaps.Red) and 4.15
(End.BM) correspond to Binding SIDs [1].
>
> As a result of 4.13 for example, the packet is encapsulated with a new
IPv6 header and an SRH that contains the SR policy associated to the BSID.
> Once the new IPv6 header is pushed into the packet, the NET-PGM
pseudocode passes this packet to the IPv6 module of the router for transmission.
>
> Normally the Upper-Layer Header should not be processed on a packet with
a BSID, since you have just pushed an SR policy into the packet.
> That said, when the ultimate destination is BSID, then the Upper Layer
Header processing is the same to End (4.1).
>
> Hope it clarifies.
I'm still not clear on things I guess, but your answer leads me to a more
basic question:
Section 4.1 described the basic "FIB entry" "End" which says:
"When N receives a packet whose IPv6 DA is S and S is a local End SID, N
does..."
So it's talking about a FIB entry for a "local End SID".
Section 4.1.1 says:
"When processing the Upper-layer Header of a packet matching a FIB
entry locally instantiated as an SRv6 End SID"
It's talking about a "FIB entry locally instantiated as an SRv6 END SID"
I'm not understanding how these 2 things are different. 4.1s calling a FIB
Entry a "local End SID" 4.1.1 is calling something (different?) a "FIB Entry
locally instantiated as an SRv6 END SID".
The terms seem too similar for me to make a distinction, where I feel the
document expects me to make one.
Thanks,
Chris.
>
> Thanks,
> Pablo.
>
> [1]. https://tools.ietf.org/html/rfc8402#section-5
>
>
> -----Original Message-----
> From: spring <spring-boun...@ietf.org> on behalf of Christian Hopps
<cho...@chopps.org>
> Date: Saturday, 7 March 2020 at 12:50
> To: "spring@ietf.org" <spring@ietf.org>
> Cc: Christian Hopps <cho...@chopps.org>
> Subject: [spring] Question on
draft-ietf-spring-srv6-network-programming-12
>
> In sections 4.13, (implicitly in 4.14) and 4.15 a set of steps is
indicated. As far as I can tell the processing of the IPv6 header chain in all
cases is terminated. e.g.,
>
> "
> When N receives a packet whose IPv6 DA is S and S is a local End.BM
> SID, does:
>
> S01. When an SRH is processed {
> S02. If (Segments Left == 0) {
> ....
> Interrupt packet processing and discard the packet.
> S04. }
> S05. If (IPv6 Hop Limit <= 1) {
> ....
> Interrupt packet processing and discard the packet.
> S07. }
> S09. If ((Last Entry > max_LE) or (Segments Left > (Last Entry+1))
{
> ....
> Interrupt packet processing and discard the packet.
> S11. }
> ....
> S15. Submit the packet to the MPLS engine for transmission to the
> topmost label.
> S16. }
> "
>
> The text then says:
>
> When processing the Upper-layer header of a packet matching a FIB
> entry locally instantiated as an SRv6 End.BM SID, process the packet
> as per Section 4.1.1.
>
> Why would I ever be processing the upper-layer header at this point?
>
> Thanks,
> Chris.
> _______________________________________________
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> spring@ietf.org
> https://www.ietf.org/mailman/listinfo/spring
>
>
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