Extreme Networks was established by co-founders Gordon Stitt, Herb Schneider, and Stephen Haddock in 1996 in California, United States, with its first offices located in Cupertino, which later moved to Santa Clara, and later to San Jose.

Extreme has publicly stated that it expects to "generate over $200 million in additional annualized revenue" from the acquired networking assets from Avaya.

[citation needed] On March 29, 2017, Extreme Networks announced its intention to acquire Brocade's SRA (Switching, Routing, and Analytics) business from Broadcom for an undisclosed sum.

The acquisition officially closed on October 30, 2017, and with it, Extreme acquires customer relationships, personnel, and technology assets from Brocade including the SLX, VDX, MLX, CES, CER, Workflow Composer, Automation Suites, and certain other Data Center related products.

Extreme Networks itself claims that the combined entity should now be able to generate annual revenues in the region of US$1 billion and to now rank in the top three enterprise networking companies (measured by revenue),[9] and Zeus Kerravala, an industry pundit, has observed that "a bigger, more profitable Extreme will have more money to invest in R&D, fueling further innovation.