Darren, I had assumed that 8754 did indeed define things the way you use
them. However, I can not find the assertions you make.
The short text in section 3.3 of RFC 6754 does not seem to create a
distinction between segment or local interface. For that to be the
justification for SIDs do not have to interfaces is putting a lot of
weight, and a significant change in the IP address architecture, on two
words in an informative paragraph.
Further, section 4.3 draws a distinction between processing a SID and
processing a packet addressed to an interface and that "is not locally
instantiated as an SRv6 SID" That does not create the distinction you
are arguing for.
Nothing in either document lays any groundwork I can see for
LOC:FUNC:ARG. On the one hand, 8402 applies to MPLS, which does not use
any such distinction. And when I search those documents, )maybe I
missed something) I did not find any references to 'arg" or "loc" that
seemed relevant.
Yours,
Joel
On 3/16/2020 12:45 PM, Darren Dukes (ddukes) wrote:
The following are some observations on SRv6 SIDs and IPv6 addressing as they
pertain to draft-ietf-spring-network-programming (NETPGM)
SRv6 RFCs tell us the following as it relates to SRv6 SIDs, IPv6 addresses and
how SIDs are identified and assigned:
- RFC8402 tells us an SRv6 SID is an IPv6 address.
- RFC8754 section 1 defines SRv6 and its instantiation in the IPv6 dataplane,
along with SID terminology
- RFC8754 section 2 defines Segment List as a list of IPv6 addresses
- RFC8754 section 3.3 defines an SR segment endpoint node, making the distinction between
"segment or local interface."
- RFC8754 section 4.3 describes processing at segment endpoint node for either;
a fib entry representing a locally instantiated SRv6 SID, or a local interface
not instantiated as a SRv6 SID.
- RFC8754 section 5 describes the Intra-SR-Domain deployment model, where:
- within the SR domain "Allocate all the SIDs from a block S/s"
- within the SR domain “Assign all interface addresses from prefix A/a"
- At node k [within the SR domain], all SIDs local to k are assigned from
prefix Sk/sk
How this relates to NETPGM
- SRv6 SIDs are IPv6 addresses.
- SRv6 SIDs are not necessarily interface addresses.
- SRv6 SIDs are allocated from S/s within the SR domain (NETPGM formalizes this
as B)
- SRv6 SIDs are locally instantiated at node k in prefix Sk/sk (NETPGM
formalizes this as LOC, or B:N for node N)
- SRv6 SIDs are locally instantiated at a node using the remaining bits of
Sk/sk (NETPGM formalizes this as FUNC:ARG)
NETPGM and the representation of a SID as LOC:FUNC:ARG are expected by RFC8402
and RFC8754 and inline with both.
NETPGM formalizes the concepts previously described, and required within the SR
domain.
Darren
_______________________________________________
spring mailing list
spring@ietf.org
https://www.ietf.org/mailman/listinfo/spring
_______________________________________________
spring mailing list
spring@ietf.org
https://www.ietf.org/mailman/listinfo/spring
