CCNA (Hindi) Day 27 | OSPF Explained Step by Step скачать в хорошем качестве

CCNA (Hindi) Day 27 | OSPF Explained Step by Step

SPF (Open Shortest Path First) neighbor relationships go through distinct states to establish full adjacency. These states, defined in RFC 2328, are: Down, Init, 2-Way, Exstart, Exchange, Loading, and Full. Each state represents a stage in the neighbor discovery and database synchronization process. Here's a breakdown of each state: 1. Down: The initial state where no OSPF information has been received from the neighbor. Hello packets can still be sent. 2. Init: The router has received a Hello packet from a neighbor, but the neighbor's Router ID is not listed in that Hello packet. 3. 2-Way: Bi-directional communication is established. The router sees its own Router ID in the neighbor's Hello packet. On broadcast and non-broadcast multi-access networks, this state also indicates the completion of DR/BDR election. 4. Exstart: The routers establish a master-slave relationship and negotiate the initial sequence number for database description packets. 5. Exchange: Routers exchange database descriptor (DBD) packets, which contain summaries of their link-state databases (LSDBs). 6. Loading: Routers request and receive detailed link-state information based on the DBDs. They send Link State Request (LSR) packets and receive Link State Update (LSU) packets. 7. Full: The routers are fully adjacent, with synchronized link-state databases. This is the normal, operational state for OSPF neighbors. #ccna #networkdiscovery #networkadministrator #internet #education #networkengineer #networktechnician #routing #ospf #router #cisco #ciscoengineer #ciscopackettracer