Sargun Dhillon

Infrastructure Generalist

A Critique of Network Design

With the advent of datacenter-level computation, networks have become key. In datacenter networks, the concerns of network engineers still primarily lie at layers 1–3. Occasionally, layer 4–6 will be inspected upon transforming packets, or making routing decisions. I’ll leave layer 1 out of this, as it’s well isolated, and well modeled at this point as asynchronous serial links. There seems to be a contention at layer 2 & layer 3 — where network builders are largely moving away from layer 3 on the fabric, as seen in draft-lapukhov-bgp-routing-large-dc. Yet, there is a massive contingent still looking to build layer 2 networks, or layer 2 overlays atop these layer 3 fabrics with technologies like VXLan. With the new ubiquity of layer 3 forwarding elements, and their reduced cost, building layer 3 topologies has now become possible. Here, I’ll dive into why these two camps, and what we can

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