Ivan Pepelnjak, CCIE No. 1354, is a 25-year veteran of the networking industry. He has more than 10 years of experience in designing, installing, troubleshooting, and operating large service provider and enterprise WAN and LAN networks and is currently chief technology advisor at NIL Data Communications, focusing on advanced IP-based networks and web technologies. His books published by Cisco Press include As was usual in the early days of the information technology (IT) industry, Ivan started as a programmer, developing device drivers and symbolic kernel debuggers back when 256 kilobytes was the size of a mainframe computer RAM, not a personal computer CPU cache size; and implementing file sharing networks over "high-speed" 38 kilobit serial connections. He started a commercial Internet Service Provider when the web was still an odd experiment within CERN, and deployed interactive web-based applications before Netscape invented JavaScript. In his role as technical director of NIL Data Communications, Ivan focused exclusively on large-scale IP networks, became one of the early Cisco Certified Internetworking Experts (CCIE) and one of the first Cisco-certified instructors. His extensive knowledge helped service providers, such as British Telecom, Deutche Telekom, France Telecom, Global One, Telia and SITA deploy large-scale state-of-the art IP or MPLS networks. Large corporations benefiting from his experience include equipment manufacturers and integrators, such as Cisco Systems, Digital, Hewlett Packard, IBM, Unisys, as well as banks (Dresdner Bank in Germany) and petroleum industry companies (Statoil in Norway). He was also able to transform the hands-on experience gained in consulting projects into an educational framework when he was one of the architects of Cisco Systems' Service Provider curriculum and the lead developer of several Service Provider-focused courses covering Border Gateway Protocol (BGP), Multi-protocol Label Switching (MPLS) and IP Quality of Service. These days, you'll likely find Ivan solving interesting networking or web-related challenges or you might find him hiking, mountain-biking or rock-climbing somewhere high in the European Alps.