In which OSPF neighbor state does the router determine if it is a Master or Slave?

In the OSPF (Open Shortest Path First) protocol, the Exstart state is crucial for the establishment of a relationship between neighbors, particularly for determining which router will take on the Master role and which will be the Slave. This phase is where routers exchange information about their database descriptions (DBDs) and establish the parameters for the subsequent exchange of routing updates.

During the Exstart state, routers use a designated router election process that defines which router will first send updates (the Master) and which router will respond (the Slave). This is important because it helps to prevent conflicts and ensures orderly communication between OSPF routers. Each router in the Exstart state sends out a DBD to its neighbor and, based on these exchanges, they'll agree on the sequence of transactions to follow.

Identifying the Master and Slave roles is essential for efficient synchronization of their routing tables. The relationship established during the Exstart state dictates how subsequent packets will be sent and acknowledged in the OSPF session. This cooperation leads to effective routing and stability in the OSPF network environment.