Re: progressing draft-ietf-rtgwg-mofrr-06 [AUTHOR RESPONSE NEEDED]

[IJsbrand Wijnands <[e-mail]>]

Hi Alia,

Thanks for your review.

See below response to your comments;

> On Thu, Apr 16, 2015 at 3:19 PM, Alia Atlas <[e-mail]> wrote:
> As is usual, I have done my AD review of draft-ietf-rtgwg-mofrr-06.  I don't have any specific comments on the text(assuming that the RFC Editor will pick up the typos I saw).  However, I do see a couple gaps that I think would be very useful to address.   Feel free to convince me otherwise - but I think these will make for a stronger RFC.
> 
> It would have been nice to have a sentence or two in there that considered the operational and troubleshooting aspects of MoFRR.  For instance, can mtrace work?  Would lsp-ping fail to work on the secondary UMH because of packets being dropped?
> 
> I also recall a private discussion about the interaction of MoFRR and IGP reconvergence after a failure and whether there can be relevant micro-forwarding loops as a result.  It would be very useful to have a sentence or two in this draft that discusses whether micro-forwarding loops are a concern that can either be frequently avoided because the secondary UMH or that needs to be considered in modeling or....
> 
> I'd welcome discussion to clarify these two aspects while the draft is in IETF Last Call.  I'd like to have these resolved by May 7 so that it can be on the IESG telechat on May 15.

You raise interesting points, but the fact is that the existing troubleshooting tools for Multicast (mtrace, ping, LSP ping) have not been modified to help troubleshoot the secondary path. So packets will get dropped due to the secondary being path being inactive and not forwarding packets. I can add that to the MoFRR draft, but I don’t think it will become a stronger RFC due to it. If customers need such troubleshooting I’m sure they will raise it and the IETF can address it. But for now my preference would be to leave it like it is and move it forward.

Regarding the micro-loops related to MoFRR. I was not involved in the private discussion you had regarding MoFRR, IGP re-convergence and loops. So I can’t really address that concern. To me it does not look any different from a normal IGP convergence with PIM and mLDP. Can clarify?

Thx,

Ice