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

[Ron Bonica <[e-mail]>]

Ole,

That's fine, but which ever way the debate ends, the draft should be consistent. IMHO, the two ways to achieve consistency are:

- Sections 4.4 - 4.12 all use 59
- Sections 4.4-4.12 all use something other than 59

                                                                          Ron


Non-Juniper

> -----Original Message-----
> From: Ole Troan <[e-mail]>
> Sent: Thursday, May 9, 2019 7:30 AM
> To: Stewart Bryant <[e-mail]>
> Cc: Ron Bonica <[e-mail]>; SPRING WG <[e-mail]>; Bob
> Hinden <[e-mail]>; 6man WG <[e-mail]>
> Subject: Re: SRv6 Network Programming: ENH = 59
> 
> >>> I suspect that we will be far more likely regret this use of 59 in the long
> term than we will regret changing to 97 at this early stage.
> >> But it’s not that nh=59 can be used to imply that Ethernet follows. That
> would be very bad.
> >> It’s that ip processing stops here.
> >> Then if the two ends have agreed the meaning of the remaining payload
> and how to process it, that’s fine. If that signaling is in-band e.g in a particular
> SID or out-of-band, the principle is the same.
> >
> > Yes, but experience suggests that having no control word and no ability to
> retrofit one is a long term problem waiting to happen.
> 
> I think this is a philosophical debate.
> Does a packet have to be entirely self-describing or can a end-point learn how
> to interpret part of a packet out-of-band.
> 
> Personally I think there is a use of nh=59 to end IP processing and allow
> further payload.
> If this particular mechanism is a good use for this particular use case of SR, I
> have no opinion.
> 
> Cheers,
> Ole