Cisco EIGRP and OSPF Training

Explore OSPF's three tables—routing, neighbor, and topology—and learn to view them with show ip ospf neighbor and show ip ospf database, including router ID, area, link ID, and sequence numbers.

Explore open shortest path first (OSPF) router types, including internal routers, backbone routers, area border routers, area border outer, and autonomous system border routers, and their roles across areas.

this lab demonstrates ospf equal-cost load balancing, clarifying that ospf does not support unequal load balancing; it uses multiple equal paths by default, adjustable with the maximum command, including subinterfaces.

This lecture explains OSPF path selection when routes come from different areas, detailing the preference order: intra-area, inter-area, external type 1, external type 2, and NSSA options, with cost considerations.

Learn how OSPF hello interval and dead interval govern neighbor relationships across broadcast, non-broadcast, and multipoint networks. Decrease these timers for faster convergence, or use BFD for rapid failure detection.

Explore how to filter OSPF routes using distribute-list and ACLs, comparing exist list, prefix list, and route map approaches, with inbound and outbound filtering.

Configure OSPF passive interfaces to stop hello packets and prevent neighbor formation, using per-interface or all-interfaces approaches to secure routing updates.

Explore how OSPF address families unify IPv4 and IPv6 under a single process, and configure them across interfaces, including IPv6 routing, with three methods: standard, interface-based, and address family.

Explore OSPF area types, from backbone area zero to normal, transit, and not so stubby and totally stubby areas, and learn how area division reduces routing overhead.

Configure and verify OSPF normal area across a three-router topology, enabling area zero and area one, redistribute connected subnets to advertise external routes, and validate with show ip OSPF database.

Configure and verify the OSPF stub area to minimize routing table size by converting area one from normal to stub, advertising area zero, and validating with show ip protocols.

Configure and verify a totally stub area in OSPF to minimize routing tables by stopping external and inter-area routes and summarizing to a default route.

Troubleshoot OSPF issues across a multi-router topology in a hands-on lab, diagnosing problems with interface states, network advertisements, area mismatches, authentication, ACLs, and router IDs to restore neighbor adjacency.

This lab demonstrates how administrative distance governs route selection among EIGRP, OSPF, and RIP; by adjusting AD with the distance command, the router chooses the most trusted protocol.