The U.S. International Trade Commission (ITC) on Tuesday made a ruling on the first of two Cisco V. Arista cases.
The patent battle began in December 2014, when Cisco alleged that Arista had repeatedly lifted the company's inventions and patents. Cisco said its intellectual property in part led to the Arista IPO earlier that year.
Weeks later Cisco petitioned the ITC for an injunction to prohibit Arista from importing and selling products using Cisco-patented technology within the United States.
With today's ruling, both sides claimed small victories, but Cisco came out on significantly higher ground.
For Cisco's side, ITC administrative law judge David Shaw found that Arista had violated three patents that cover software features used in the company's switching systems. Details of the ruling also state that Arista could be forced to halt all imports of its switches if the ruling gains final approval by the commission.
"Arista can no longer support claims to customers, resellers, and the market that they created products from 'a clean sheet of paper,'" Cisco general counsel Mark Chandler said in a statement.
"The patents in question go to the core of Arista's products. One of those found to infringe covers Cisco's proprietary 'SysDB.' Arista's CEO has previously referred to 'SysDB' as Arista's 'secret sauce' and more recently, the architecture on which NetDB is built."
Cisco has asserted that all of the patents in question stem from technology that was invented by Cisco employees who later became executives at Arista, or by engineers who worked for Arista executives while employed at Cisco.
Arista, meanwhile, has vehemently denied the allegations of patent infringement. The ITC today determined that Arista did not infringe two of the five patents in question.
"We strongly believe that we have not infringed any of the patents ... and look forward to the final determination" in June, the Santa Clara, Calif., company said in a statement.
Cisco's initial lawsuit concerned 12 features covered by 14 patents -- all of which are embedded within current Arista products. At the judge's request, Cisco whittled the list down to six -- then eventually five -- offending patents for the first lawsuit.
Going forward, the two tech rivals will face another ruling in April for the second ITC investigation concerning the remaining six patents, which Cisco said could confirm more violations and import bans against the networking company.