Focus & Learn

  What is the EIGRP EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco proprietary protocol, it uses a combination of distance-vector and link-state routing protocols. This technically makes EIGRP an advanced distance-vector protocol or a hybrid protocol. Administrative Distance for EIGRP are: - EIGRP Routes AD Values Summary Routes 5 Internal Routes 90 External Routes 170 Some messages to communicate with the neighbour devices that operate EIGRP. These are: Hello messages,   Used for neighbor discovery and maintaining adjacencies. Update messages, Contain routing information sent to neighbors. Query Messages, Sent when a router needs additional information about a destination. Reply Messages, Sent in response to query packets. Acknowledgement messages, Confirm the receipt of reliable packets. Here Update, Query, and Reply messages contain RTP - Reliable Transport Protocol . EIGRP Update and Discovery Process -  EIGRP Simplified the Formula,  Here,...

  What is the OSPF Routing Protocol and Brief in details OSPF stands for Open Shortest Path First, is a Link State Routing Protocol which is used to find the best path between source to destination router using the Shortest Path First Algorithm. OSPF maintain three main categories -  Neighbors Database Exchange Route Calculation How OSPF Works - Link-State Advertisements (LSAs): OSPF routers exchange LSAs to share information about their links, states, and costs. Topology Database: Each router builds a link-state database (LSDB) based on received LSAs. SPF Calculation: OSPF uses the Dijkstra algorithm to compute the shortest path to all destinations in the network. Routing Table Update: The results of the SPF calculation populate the routing table with the best routes. Convergence: OSPF quickly converges after a topology change by recalculating paths. OSPF Metrics Calculation -  Cost = Reference Bandwidth (Mbps) / Interface Bandwidth (Mbps) 'OR' Cost = 10^8/Bandwidth Here...