In the network layer, routing information is used to determine a path to a destination. Packets are used here. This includes routing protocols, logical network addresses, and packet fragmentation. The router handles these things. By using the network layer, data sequences (called packets) can be transmitted between nodes in different networks. It allows packets to be routed between two or more nodes (without having to establish a direct physical connection) by transferring them over many intermediate nodes. It may be necessary for Layer 3 devices to know how to reach various network addresses based on logical network addresses. Typical Layer 3 devices include routers. Based on a packet’s destination network address, a router can maintain a routing table that indicates how to forward the packet. In addition to manual configuration (that is, entering static routes), a router can have its routing table populated via a dynamic routing protocol (for example, OSPF or EIGRP) or simply by directly connecting to certain networks.
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