Re: [spring] SRv6 Network Programming: ENH = 59

[Ron Bonica <[e-mail]>]

Pablo,

I am not sure that your use of this field is in accordance with Section 4.7 of RFC 8200.

                                                                    Ron



Juniper Internal

> -----Original Message-----
> From: Pablo Camarillo (pcamaril) <[e-mail]>
> Sent: Tuesday, May 7, 2019 3:09 AM
> To: Ron Bonica <[e-mail]>; SPRING WG <[e-mail]>; 6man
> WG <[e-mail]>
> Subject: Re: SRv6 Network Programming: ENH = 59
> 
> Hi Ron,
> 
> We use the next header value 59 to identify at the receiver that there is no
> other kind of Internet Protocol beneath to be processed.
> Note that we are *not* using 59 to identify the fact that it is an ethernet
> header (i.e. other non Internet-Protocols would also use the 59 to identify that
> no further IP header processing has to be performed). The SID identifies that
> an Ethernet header follows the IPv6 extension headers.
> 
> Thanks,
> Pablo.
> 
> -----Original Message-----
> From: ipv6 <[e-mail]> on behalf of Ron Bonica
> <rbonica=[e-mail]>
> Date: Monday, 6 May 2019 at 02:48
> To: SPRING WG <[e-mail]>, 6man WG <[e-mail]>
> Subject: SRv6 Network Programming: ENH = 59
> 
>     Folks,
> 
>     According to Section 4.4 of draft-ietf-spring-srv6-network-programming-
> 00, when processing the End.DX2 SID, the Next Header must be equal to 59.
> Otherwise, the packet will be dropped.
> 
>     In the words of the draft, "We conveniently reuse the next-header value 59
> allocated to IPv6 No Next Header [RFC8200].  When the SID corresponds to
> function End.DX2 and the Next-Header value is 59, we know that an Ethernet
> frame is in the payload without any further header."
> 
>     According to Section 4.7 RFC 8200, " The value 59 in the Next Header field
> of an IPv6 header or any  extension header indicates that there is nothing
> following that header.  If the Payload Length field of the IPv6 header indicates
> the presence of octets past the end of a header whose Next Header field
> contains 59, those octets must be ignored and passed on unchanged if the
> packet is forwarded."
> 
>     Does the WG think that it is a good idea to reuse the Next Header value 59?
> Or would it be better to allocate a new Next Header value that represents
> Ethernet?
> 
>                                                               Ron
> 
> 
>     Juniper Internal
> 
>     --------------------------------------------------------------------
>     IETF IPv6 working group mailing list
>     [e-mail]
>     Administrative Requests:
> https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__www.ietf.org_mailman_listinfo_ipv6&d=DwIGaQ&c=HAkYuh63rsuhr6S
> cbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-
> AWF2EfpHcAwrDThKP8&m=YOpkfRdJqwMPig1QVXflyp_jPXFxMtT_wCSFm0
> 9x7uQ&s=dwc4VotN_cH4V8ncfopG-fNWOmJVYzMQLduXjOLwIWM&e=
>     --------------------------------------------------------------------
> 
>