Again, it depends. DFs at the edge as you're talking about are tricky. We worked on some designs a couple years ago. FIB management can become really tricky, with a lot of big peers and/or connections to the DFZ. If you do it wrong you can get tricky hotspotting or bouncing issues with your N/S traffic. It's doable of course, but in many circumstances I think these make the most sense down in the aggregation layers of a design. On Thu, Dec 26, 2024 at 9:30 PM Mike Hammett <nanog@ics-il.net> wrote:
*nods* Yeah, I knew that's how a traditional chassis worked. In a distributed setup, you have the option for a single "line card", which obviously doesn't happen in the traditional chassis world.
I do see in a DDCv2 document where they briefly mention 2 compute boxes, so now that makes sense. I had to look up some of the acronyms because the document didn't define them within itself.
----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Randy Bush" <randy@psg.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, December 26, 2024 4:51:45 PM *Subject: *Re: Distributed Router Fabrics
In a distributed fabric, where is the traditional control plane run? Say I've got 100 BGP sessions of upstream,peer, and downstream across ten routers. Is each pizza box grinding this out on its own, or is the work done on the x86 box mentioned in the larger installations?
one way to think of it is that each pizza box (customer facing ports) recognizes control plane messages (e.g. port 179) and "punts" them to the control plane box, aka routing engine.
fwiw, that is pretty much what line cards on a big-box fabric do, punt to the RE.
randy