Hi Mark, Tcpdump/wireshark decodes the IPv6 header just fine. I do not see any issue here.
Cheers, Francois On 4 Apr 2024 at 14:09:43, Mark Smith <markzzzsm...@gmail.com> wrote: > > > On Thu, 4 Apr 2024, 22:50 Francois Clad, <fclad.i...@gmail.com> wrote: > >> Hi Alvaro, all, >> >> RFC 8754 allows the SR source node to omit the SRH when it contains >> redundant information with what is already carried in the base IPv6 header. >> Mandating its presence for C-SID does not resolve any problem because it >> will not provide any extra information to the nodes along the packet path. >> > > How are troubleshooting tools like 'tcpdump' going to know how to > automatically decode these packets as SRv6 packets if there is no SRH? > > > >> Specifically for the case of middleboxes attempting to verify the >> upper-layer checksum, >> >> - An SRv6-unaware middlebox will not be able to verify the >> upper-layer checksum of SRv6 packets in flight, regardless of whether an >> SRH is present or not. >> - An SRv6 and C-SID aware middlebox will be able to find the ultimate >> DA and verify the upper-layer checksum in flight, regardless of whether an >> SRH is present or not. >> >> >> Furthermore, transit nodes (e.g., middleboxes) should not attempt to >> identify SRv6 traffic based on the presence of the SRH, because they will >> miss a significant portion of it: all the best-effort or Flex-Algo traffic >> steered with a single segment may not include an SRH, even without C-SID. >> Instead, RFC 8402, 8754, and 8986 define identification rules based on the >> SRv6 SID block. >> >> Thanks, >> Francois >> >> >> On 2 Apr 2024 at 19:44:51, Alvaro Retana <aretana.i...@gmail.com> wrote: >> >>> [Moving this conversation up on your mailbox. :-) ] >>> >>> [Thanks, Robert and Tom for your input!] >>> >>> >>> We want to hear from more of you, including the authors. Even if you >>> already expressed your opinion in a different thread, please chime in here. >>> >>> We will collect feedback until the end of this week. >>> >>> Thanks! >>> >>> Alvaro. >>> >>> On March 28, 2024 at 8:06:18 AM, Alvaro Retana (aretana.i...@gmail.com) >>> wrote: >>> >>> >>> Focusing on the C-SID draft, some have suggested requiring the presence >>> of the SRH whenever C-SIDs are used. Please discuss whether that is the >>> desired behavior (or not) -- please be specific when debating the benefits >>> or consequences of either behavior. >>> >>> Please keep the related (but independent) discussion of requiring the >>> SRH whenever SRv6 is used separate. This larger topic may impact several >>> documents and is better handled in a different thread (with 6man and spring >>> included). >>> >>> Thanks! >>> >>> Alvaro >>> -- for spring-chairs >>> >>> -------------------------------------------------------------------- >>> IETF IPv6 working group mailing list >>> i...@ietf.org >>> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 >>> -------------------------------------------------------------------- >>> >> -------------------------------------------------------------------- >> IETF IPv6 working group mailing list >> i...@ietf.org >> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 >> -------------------------------------------------------------------- >> >
_______________________________________________ spring mailing list spring@ietf.org https://www.ietf.org/mailman/listinfo/spring
