ANET is down 3.8% after hours.
The commission also recommended an import ban on Arista's infringing products. The patents in question have to do with managing and securing communications networks.
While the ITC has granted the import ban, it may take resolution of the two companies' ongoing countersuits to settle any damages.
An administrative law judge had previously found that Arista had infringed Cisco's '537, '592 and '145 patents.
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