Cisco CCNA 200-301: Routing, IPv4, IPv6 & OSPF (Part 3/6)

learn static routing by manually configuring routes as an administrator, comparing possible paths from A to B, and recognizing its limited scalability for large networks compared to dynamic routing.

Learn to configure static routes by manually specifying destination networks and next-hop addresses, verify routing tables, ensure interfaces are up, and test connectivity with tracer.

Build the routing table by validating next hops and reachability, applying the longest prefix match, and using administrative distance and metrics to select routes, including static routes.

Understand how routing lookup selects the next hop using the gateway and default gateway, examines the routing table, and forwards packets between networks, while troubleshooting missing entries.

Establish prerequisites for routing topics by reviewing basic connectivity, interface verification with show ip interface brief, and introducing IGP and dynamic routing concepts including ISIS basics for IPv4/IPv6.

Learn how ospf forms neighbor relationships, builds the link-state database, exchanges routing information, and selects the best paths to forward traffic across networks.

Learn how OSPF builds the link-state database by exchanging hello messages to form neighbors, flood LSAs, and ensure all routers share topology information.

Synchronize the OSPF LSDB across neighbors by exchanging missing entries during loading to achieve a full state, then apply the shortest path algorithm to determine best route for routing table.

Learn how to configure OSPF single area by advertising two interfaces, setting networks, area numbers, and verifying neighbor adjacency with proper subnet masks and /30 point-to-point links.

Verify single-area OSPF by checking neighbor adjacencies, protocol database, and routing table entries; confirm router-id selection, interface IP addresses, and OSPF cost using show ip protocols and show ip ospf.

Examine how OSPF advertisements select interfaces through wildcard masks, with concrete examples showing advertising specific interfaces, all interfaces, or subsets across a topology.

Explain the default reference bandwidth limitations in routing cost calculations. Show how high-speed links lose differentiation, treating 10/100 gig lanes as the same cost, which hinders optimal path selection.

Adjust the auto cost reference bandwidth to scale link costs. Calculate that the cost equals reference bandwidth divided by interface bandwidth, and you can also set manual per-interface costs.

Learn to advertise OSPFv2 routes using interface-based advertisements as an easier alternative to network statements, enabling OSPF on interfaces and automatically publishing connected subnets by area.

Explain ipv6 address types, including global unique (starts with 2000/3), unique local (fc or fd), link-local, multicast, and anycast, noting no broadcast in ipv6 and use of anycast for clusters.

Explore first hop redundancy protocols, including HSRP, VRRP, and GLBP, to create a virtual gateway that aggregates two physical gateways for seamless failover and reduced downtime.