Microsoft accounted for 26% of Arista Networks’ 2025 revenue, growing its network spending by 67% year over year and contributing approximately $1 billion in incremental sales despite limited Ethernet at scale. Most growth stemmed from front-end switching projects in major data centers.

A $2.5 billion increase in deferred revenue suggests significant unrecognized sales that will likely roll into future quarters as deployment milestones are met. If Microsoft accelerates its Ethernet deployments in Fairwater data centers, Arista stands to convert a larger portion of these deferred orders into recognized revenue in 2026.