Re: [Idr] I-D Action: draft-ietf-idr-rs-bfd-03.txt

[Job Snijders <[e-mail]>]

On Tue, Jul 04, 2017 at 01:58:27PM -0400, Jeffrey Haas wrote:
> On Mon, Jul 03, 2017 at 08:27:20PM +0000, Job Snijders wrote:
> > As a generalized mechanism, IXPs could snoop BFD traffic to
> > disseminate the current state of reachability on the fabric, such
> > BFD snooping would work for both RS peers as well as bilateral
> > peers.
> 
> I must admit to being boggled at expecting IXP switch fabric endpoints
> being expected to sniff on a chatty protocol to derive state.  Why do
> you think this makes sense?

Because some IXPs already use 'snooping' style methods, this is not my
own idea. For instance VIX offers insight into who peers with who at
https://www.vix.at/vix_peeringmatrix_detail_ipv6.html (page may take up
to 60 seconds to load) based on a form of snooping, some other IXPs
snoop ('intercept') ARP traffic to prevent unnecessary chatter. This
isn't new.

> > A question would be "why impose additional reporting duties (load)
> > on the RS peers when the IXP can glean similar information through
> > snooping"?
> 
> There's also the matter that the fabric isn't necessarily aware of the
> semantics of a session.  It would have to report up to some central box
> anyway.

Yes, but that box wouldn't be the same box as the route server.

Kind regards,

Job