nanog mailing list archives

Re: Brocade SLX Internet Edge


From: Blake Hudson <blake () ispn net>
Date: Thu, 1 Nov 2018 13:55:38 -0500


Chris Welti wrote on 11/1/2018 10:03 AM:
Nicolas Fevrier has a very detailed blog post on how Cisco handles the prefixes on their Broadcom Jericho based NCS 
5500 gear.
https://xrdocs.io/cloud-scale-networking/tutorials/2017-08-03-understanding-ncs5500-resources-s01e02/

I'm pretty sure the principle is more or less the same for the Jericho based platforms on Arista and Extreme.

Best regards,
Chris

I love the nitty gritty detail in this author's post and I'm glad he concludes by stating clearly that while the base card (spec sheet says: "On-chip tables for 256K IPv4 or 64K IPv6 routes" and "On-chip tables for 786K IPv4 host routes, MAC, and labels") can actually hold a full BGP table today when configured appropriately, Cisco still recommends the scale cards for that application (spec sheet says: "FIB scale up 2M IPv4 or 512K IPv6 routes" and "On-chip tables for 786K IPv4 host routes, MAC, and labels").

I do have to wonder about the internal expansion of each /23 route into two /24 routes in their FIB algorithm, as I would have thought Cisco would have attempted to go the opposite way, but I'm sure Cisco has their reasons.


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