Cisco Certified Internetwork Expert (CCIE) is what Cisco describes as its "premium networking certification." The CCIE is widely regarded as having one of the toughest, most demanding exams. It includes both a written exam and a day-long lab exam. This certification is aimed at senior level networking professionals who design, build, implement, maintain, or troubleshoot complex enterprise networking infrastructures. CCIE recipients can specialize in routing and switching, communications and services, security, or voice systems and technologies.