Network Appliance Inc., which makes network-attached storage systems, said Sept. 5 it filed a patent lawsuit against Sun Microsystems Inc. in the wake of “prolonged and aggressive claims” by Sun against the company.

NetApp said its lawsuit seeks a declaration that it is not infringing three of Sun’s U.S. patents and that those patents are invalid. The suit also seeks a ruling that Sun infringes seven of NetApp’s U.S. patents pertaining to data processing systems and related software.