Most routing protocols have metric structures and algorithms that are not compatible with other protocols. In a network with multiple routing protocols, the exchange of route information and the capability to select the best path across the multiple protocols are critical.elect the Best Path. Administrative distance is the first criterion that a router uses to determine which routing protocol to use if two protocols provide route information for the same destination. Administrative distance is a measure of the trustworthiness of the source of the routing information.
In July 2013, China heralded the opening of the New Century Global Center, an immense 18.9-million-square-foot (1.75 million square meters) structure that many are calling the largest building in the world.
It's official: New York City's One World Trade Center is now the nation's tallest building, wresting the title from Chicago's Willis Tower, which claimed the top spot for 40 years. It also leapfrogged the 1,667-foot Taipei 101 in Taiwan to become the third largest building in the world.