Amit Patel

While no one ever claimed firewall migration was easy, it's grown considerably harder over the past three years, says Amit Patel, director of product marketing and security management at Cisco.

"It's really the last three years when there were significant enhancements [to firewalls] by vendors," Patel says."It's made migration more difficult."

He recommends that network professionals document their firewall configurations and access rules as comprehensively as possible before migration.