Cisco: The Incumbent Arista Already PassedWide moat

Arista overtook Cisco as the largest data-centre Ethernet switch vendor in 2024, which remains one of the more remarkable competitive outcomes in enterprise technology: a company founded in 2004 taking the most valuable segment of networking from the firm that invented the category.

Cisco is far from beaten. It still holds roughly 29.8% of the overall Ethernet switch market and books billions per quarter in networking, and its installed base, channel and enterprise relationships are things Arista is only beginning to build. What Cisco has lost is the segment where buying decisions are made by engineers rather than by procurement — the hyperscalers, who evaluated both and chose the better operating system.

The competitive dynamic between them has also become less important than it was, because both are now responding to the same third party. Cisco's data-centre business grew about 16.9% year on year¹ in a market growing near 40%, which means it is losing share to Arista and Nvidia simultaneously.

Watch Cisco's data-centre growth rate rather than its total share. Total share reflects an installed base accumulated over thirty years; the growth rate reflects what buyers are choosing now — and it is the number that determines whether Cisco stabilises or continues to give ground.