An International Trade Commission (ITC) staff recommendation has landed in favor of Cisco in the router giant's legal spat with Arista Networks.

ITC staff attorneys believe Arista really did infringe on three Cisco patents, according to a report in Investor's Business Daily. The staff's findings were issued on Wednesday.

Cisco filed two patent lawsuits against Arista in U.S. District Court in December. Weeks later, Cisco filed two complaints with the ITC, and the lawsuits have been tabled until the ITC makes its decisions.

One ITC hearing began this week, but an initial determination isn't due until January, and the hearing won't reach completion until May. The other ITC hearing begins in November and has a correspondingly long wait ahead of it.

The bottom line, as Arista has stressed to investors, is that not much is likely to happen until mid-2016. Still, IBD observed that Arista's stock price dropped 5.6 percent after the ITC staff issued its findings.

It's continued to fall from there, down another 5 percent on Wednesday and 6 percent on Thursday. At press time on Friday, Arista shares were down $6.97 (10%) on the day, at $62.91.

The patent case hasn't had much impact on Arista's sales. And while the lawsuits did cause a dip in Arista's share price at first, the stock recovered, trading at more than $87 as recently as June.

Cisco's original lawsuits listed 12 patents that Arista allegedly infringed upon. Some of those charges have already been dismissed in the U.S. District Court case, as has Cisco's accusation that Arista "willfully" infringed, a charge that would have opened the possibility of stiffer penalties against Arista.