Data Autobahn Blog

Apstra DC-Fabric under the Hood - Part 1: Underlay

Apstra abstracts a lot – but those who truly understand DC fabrics look under the hood. This post dissects the underlay design of a Juniper 3-stage Clos fabric: from IP addressing to eBGP with individual spine ASNs and the BGP policies that prevent routing loops.

May 31, 2026 · Benjamin Härtel