Network security firm Palo Alto Networks Inc.'s (PANW) IPO rose in early trading Friday after pricing above a boosted range.

The company's stock opened at $55.15 a share on the New York Stock Exchange, up 31% from its initial public offering price of $42. A total of 6.3 million shares were sold in Palo Alto's offering--1.5 million of which came from prior owners--at a price above its expected $38 to $40 range, which was raised earlier this week from its original level of $34 to $37. The company sold a 9% slice of its outstanding shares.

Palo Alto makes hardware and software that provides computer-network security, addressing everything from data center to mobile device usage. Its products are used to replace older systems operated by companies or government agencies, and Palo Alto says it reduces expenses for its customers by simplifying network-security systems.

The centerpiece of Palo Alto's system is its next-generation firewall.