In a dispute that dates back to December 2014 when Cisco filed several lawsuits against Arista alleging the vendor infringed on multiple Cisco patent, Arista have been dealt another bad hand by the U.S government this week.  Arista Networks Inc’s request to set aside an order blocking importation of some of Arista’s network switch was rejected by the International Trade Commission (ITC), setting them back in the bigger case with Cisco.

As the current case stands, the ITC has found that Arista’s switches infringed two Cisco patents and banned Arista from importing the infringing products into the United States. Once this statement was released, however, the US Patent and Trademark Office declared the two Cisco patents invalid, hence the urge from Arista to cancel the import ban sentenced.

This week, though, the ITC decided that the Patent Office rulings “do not constitute a changed circumstance such that the remedial orders should be rescinded.”

Marc Taxay, senior vice president and general counsel of Santa Clara, California-based Arista, said in a statement on Thursday that the company was “deeply disappointed” in the ruling, which he called a departure from established law. Taxay said Arista will appeal the ruling and will also be releasing modified products to maintain the supply of its products in compliance with the ITC’s decision.

Cisco brought multiple lawsuits against Arista in 2014, alleging it brazenly copied Cisco’s intellectual property. Their Senior Vice President, General Counsel Mark Chandler, said the ITC send “a strong message to Arista that its corporate culture of copying” must stop.

Shares of Arista stock traded down more than 3 percent at $151.81 Friday afternoon after the ITC denied the vendor’s request to lift the ban.