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.
Burj Dubai (The 'Dubai Tower') According to Wikipedia: Burj Dubai in Dubai, United Arab Emirates is currently the world's tallest man-made structure. As of 26 September 2008, the building, which is still under construction, stood at 707 m (2,320 ft). When completed, it is expected to rise over 818 m (2,684 ft).