Hi Manav,
thank you for sharing insight view of discussions around RFC 7130, extremely
helpful.
We believe, and Jeff is co-author of RFC 7130 too, that MC-LAG presents
different case and the compromise that you’ve pointed too is justified. We will
add more details on the potential differences between unicast and multicast
fast paths in the next update.
We are open to the discussion and always welcome comments and alternative
proposals.
Regards,
Greg
From: Manav Bhatia [mailto:[email protected]]
Sent: Thursday, April 07, 2016 7:39 PM
To: Mach Chen
Cc: Gregory Mirsky; [email protected]; [email protected];
[email protected]; [email protected];
[email protected]; Alia Atlas ([email protected])
Subject: Re: Two new drafts on (micro-)BFD over MC-LAG interfaces
I believe it had to do with multicast datapath (especially link local) being
different from the unicast datapath in most routers. Using link local multicast
IP addresses may not necessarily guarantee Unicast IP reachability.
When writing 7130 we spent quite a bit of time ensuring that we dont carve out
a special data path for the micro-BFD packets. Using link local would have made
it a lot simpler.
And this is where i think the current proposal is flawed -- they use link local
multicast to ensure IP unicast reachability which is incorrect.
Cheers, Manav
On Thu, Apr 7, 2016 at 11:16 PM, Mach Chen
<[email protected]<mailto:[email protected]>> wrote:
Hi Greg and all,
I just have quick review on the drafts. If my understanding is correct, the
idea is to use multicast destination address other than unicast address when
sending BFD packets over LAG links. And actually this idea has been proposed in
https://tools.ietf.org/html/draft-chen-bfd-interface-00 (the predecessor of RFC
7130). And at that time, the co-authors of RFC 7130 did discuss the idea of
using multicast destination address, but for some reason I forget now(I may
need to reiterate the discussions on the archive), the idea was abandoned,
although I still think multicast destination address is a smart idea.
Best regards,
Mach
________________________________
From: Rtg-bfd [[email protected]<mailto:[email protected]>] on
behalf of Gregory Mirsky
[[email protected]<mailto:[email protected]>]
Sent: Tuesday, April 05, 2016 6:16
To: [email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>
Cc:
[email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>; Alia Atlas
([email protected]<mailto:[email protected]>)
Subject: Two new drafts on (micro-)BFD over MC-LAG interfaces
Dear All,
two new drafts, related to RFC 7130, were published before the meeting:
• BFD on MC-LAG interfaces in IP
network<https://tools.ietf.org/html/draft-tanmir-rtgwg-bfd-mc-lag-ip-00>
• BFD on MC-LAG interfaces in IP/MPLS
network<https://tools.ietf.org/html/draft-tanmir-rtgwg-bfd-mc-lag-mpls-00>
Greatly appreciate your reviews, comments, questions and suggestions.
Regards,
Greg
