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 has a roof height of 828 m (2,717 ft), and with its antenna included, it stands a total height of 829.8 m (2,722 ft), making it the tallest building and the tallest structure in the world. Construction of the Burj Khalifa began in 2004, with the exterior completed 5 years later in 2009. The primary structure is reinforced concrete. The building was opened in 2010 as part of a new development called Downtown Dubai.