Ivan Pepelnjak, CCIE No. 1354, has more than 15 years of experience in designing, installing, troubleshooting, and operating large service provider and enterprise IP-based networks and security solutions. He is currently chief technologies advisor at NIL Data Communications, where he designed NIL’s Service Provider Academy program. He was one of the architects of the Cisco Systems Service Provider curriculum. He also was the lead developer of several service provider–focused courses covering Multiprotocol Label Switching (MPLS), Border Gateway Protocol (BGP), and IP quality of service. Ivan has written four books for Cisco Press, covering Enhanced Interior Gateway Routing Protocol (EIGRP), MPLS, and virtual private networking (VPN) technologies.