ABSTRACT
This chapter presents the forwarding tables, analyzes the path selection process, and illustrates the Link State Database (LSDB) structure of Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS) under different scenarios. It also analyzes the path selection process and the structure of the forwarding tables obtained with IPv4 and IPv6 routing protocols. The chapter considers the forwarding tables obtained with IPv4 IS-IS, OSPFv2, and OSPFv3 and shows the LSDB structure of networks connected to other Autonomous Systems (AS) and discusses how the LSDB accommodates default routes. It also illustrates the OSPF E-type metrics and explores the LSDB structure of OSPF networks connected to a RIP domain of the same AS. The chapter focuses on OSPFv3 and IPv4 IS-IS since the technologies resort to locally generated tags to uniquely identify links and explains several experiments that illustrate the use of the E-type metric of OSPF.
