© 2013 IEEE. The Named-data Link State Routing protocol (NLSR) is a protocol for intra-domain routing in Named Data Networking (NDN). It is an application level protocol similar to many IP routing protocols, but NLSR uses NDN's interest/data packets to disseminate routing updates, directly benefiting from NDN's built-in data authenticity. The NLSR design, which was first developed in 2013 and deployed on the NDN test bed in August 2014, has undergone significant changes. Following an application-driven design approach, NLSR's development helped drive the development of the trust/security functionality of NDN libraries as well as a number of features in NDN's forwarding daemon and ChronoSync. In this paper, we describe the current design and implementation of NLSR, with emphasis on those features that differentiate it from an IP-based link state routing protocol: 1) naming: a hierarchical naming scheme for routers, keys, and routing updates; 2) security: a hierarchical trust model for routing within a single administrative domain; 3) routing information dissemination: using ChronoSync to disseminate routing updates; and 4) multipath routing: a simple way to calculate and rank multiple forwarding options. Although NLSR is designed in the context of a single domain, its design patterns may offer a useful reference for future development of inter-domain routing protocols.