The two network security firms have been embroiled in litigation in Delaware since 2011 when Sunnyvale-based Juniper Networks sued Palo Alto Networks for stepping on a half-dozen key patents related to firewall technology.
But this week Palo Alto Networks fired back with its own patent suit in the Northern District of California as well as with an unusual state court action arguing the so-called assignor estoppel doctrine, which says a patent’s former owner cannot later challenge its validity, violates California’s expansive non-compete laws.
