Hi Glen,
thank you for your question. I would not say that GAL label “exists only for
the BFD packets”. This special purpose label can be used in infinite number of
scenarios, including MC-LAG environment. But I agree, as in the
draft-tanmir-rtgwg-bfd-mc-lag-ip, we make certain assumptions about the
forwarding engines and whether proper processing of MPLS encapsulated packet
may be interpreted as indication of properly functioning Layer 2 and/or Layer
3. Or, what may more important for monitoring link layer, failure detected with
MPLS encapsulation may be interpreted as indication of a defect in Layer 2
and/or Layer 3.
Regards,
Greg
From: Glen Kent [mailto:[email protected]]
Sent: Wednesday, April 13, 2016 6:08 AM
To: Gregory Mirsky
Cc: Jeffrey Haas; Greg Mirsky; [email protected];
[email protected]; [email protected]; Alia Atlas ([email protected]); Reshad
Rahman (rrahman); [email protected]; [email protected]
Subject: Re: Two new drafts on (micro-)BFD over MC-LAG interfaces
Gregory,
You are using a special GAL label for BFD packets. This label exists only for
the BFD packets.
How can you then claim connectivity for other traffic which will not use this
label?
Glen
On Wed, Apr 13, 2016 at 4:18 AM, Gregory Mirsky
<[email protected]<mailto:[email protected]>> wrote:
Hi Jeff,
thank you for adding more details to the discussions before RFC 7130. We have
submitted another draft that proposes to use MPLS encapsulation of BFD control
packets over MC-LAG interfaces. Would greatly appreciate reviews, questions and
comments on
draft-tanmir-rtgwg-bfd-mc-lag-mpls<https://tools.ietf.org/html/draft-tanmir-rtgwg-bfd-mc-lag-mpls-00>.
Regards,
Greg
-----Original Message-----
From: Jeffrey Haas [mailto:[email protected]<mailto:[email protected]>]
Sent: Monday, April 11, 2016 10:24 AM
To: Greg Mirsky
Cc: Reshad Rahman (rrahman);
[email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>; Alia Atlas
([email protected]<mailto:[email protected]>);
[email protected]<mailto:[email protected]>;
[email protected]<mailto:[email protected]>
Subject: Re: Two new drafts on (micro-)BFD over MC-LAG interfaces
Greg,
This is more of a general comment on discussions from the development from RFC
7130 than any specific comment on your draft.
On Fri, Apr 08, 2016 at 11:43:18AM -0700, Greg Mirsky wrote:
> yes, link local multicast may be used in MC-LAG scenario. The draft
> states that it MAY be used while the broadcast has SHOULD normative.
> But we are all open to the discussion.
During our discussions across multiple vendors, including some hardware
vendors, it was determined that attempts to exercise the layer 3 mechanisms
would vary significantly across implementations depending on how packets were
encapsulated. Multicast in particular provided some problematic issues for us
beyond the initial bootstrapping phase of LAG for BFD wherein we might not have
ARP completed.
My recommendation is to proceed with your drafts with similar caution. Try to
stay as true to pure IP as possible to best insure the L3 data paths are
exercised across implementations from various vendors.
-- Jeff (speaking as an individual contributor)
