The Customers Who Could Build It ThemselvesNarrow moat
Arista Networks (ANET) — moat facet
A buyer that credibly could build its own has permanent leverage, whether or not it ever does.
The uncomfortable feature of Arista's customer base is that its two largest customers are among the handful of organisations in the world that could replace it. They have the engineering depth, the volume to justify the investment, and — through merchant silicon from Broadcom and contract manufacturers — access to the same hardware Arista uses.
White-box switching is the standing version of this threat and is examined elsewhere in this company's pages. What the customer relationship adds is leverage: a buyer that credibly could build its own has a permanent negotiating advantage, whether or not it ever does. Arista's filing notes that large customers may elect to re-assign allocations to multiple vendors based on specific requirements1, which is the polite description of that leverage.
Arista's defence is the one thing that does not come with the silicon: EOS, and twenty years of operational software that a hyperscaler would have to write and then maintain forever. Several have tried partial versions and continue to buy Arista for the demanding tiers.
Watch for a titan announcing an internally developed switching platform at scale. It would not end Arista's relationship with that customer immediately, and it would reset every price negotiation that followed — which is how this risk actually arrives.
The white-box option and the customers' own engineering capability are permanent features rather than new developments, and EOS remains the reason the titans keep buying rather than building for the demanding tiers. Nothing changed this year. The risk arrives as a price negotiation long before it arrives as a lost customer.
The largest customers could build their own switches; what stops them is the operating software Arista keeps developing. R&D growing with revenue keeps that gap open.
Source: Arista Form 10-K, FY2025 ↗- ReportedArista's filing notes that large customers may elect to re-assign allocations to multiple vendors based upon specific requirements.Arista Networks Form 10-K, FY2025 — two customers accounted for more than 10% of total revenue in each of the last three years; sales to one end customer represented 16%, 15% and 21% of total revenue and sales to the other end customer represented 26%, 20% and 18% of total revenue for the years ended December 31, 2025, 2024 and 2023 respectively; the company notes unpredictability in the timing and volume of large customer orders, that large customers may receive lower pricing terms due to volume discounts or may elect to re-assign allocations to multiple vendors based upon specific requirements, and that it continues to diversify its enterprise customers across media and entertainment, healthcare, oil and gas, education, manufacturing and industrial sectors — FY2025 (ended December 31, 2025) · publ. February 17, 2026 · source ↗