Martha Steenstrup Nimrod is a scalable routing architecture designed to support a dynamic internetwork of arbitrary size, to provide service-specific routing in the presence of multiple constraints, and to admit incremental deployment throughout an internetwork. The key features of Nimrod include representation of internetwork connectivity and services in the form of maps at multiple levels of abstraction; source- and destination-controlled route generation and selection based on maps and traffic service requirements; and source- and destination-controlled message forwarding according to the routes selected. This document contains a description of Nimrod functionality and a specification of the protocols constituting Nimrod. In particular, the operations pertinent to the map, locator, adjacency, route, and forwarding databases are described, and the Reliable Transaction, Update, Query-Response, Path Management, and Discovery protocols are specified.