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layer 2 networking (L2)

Based on the search results, layer 2 refers to the data link layer in the OSI and TCP/IP network models. Layer 2 handles local data transfer over the physical medium while layer 3 handles global routing. Understanding what happens at each layer helps troubleshoot connectivity issues and optimize network performance.

Layer 2 handles the transfer of data frames between network nodes on the same local area network (LAN) or wide area network. It provides services like framing, addressing, flow control, error detection, etc. to allow communication over the physical layer.
The main layer 2 protocol is Ethernet, which uses MAC addressing to identify devices. Other common layer 2 protocols and technologies include ATM, Frame Relay, VLANs, spanning tree, CDP, LLDP, etc.
Key functions of layer 2 include media access control, logical link control, MAC address learning, VLAN tagging, link aggregation, and spanning tree protocol.
Layer 2 mapping provides visibility into how devices are interconnected through switches, including switch-to-switch connections. This helps identify issues and optimize network configuration.
The differences between layer 2 and layer 3 are that layer 2 handles local delivery of frames while layer 3 handles global addressing and routing of packets between networks. Routers primarily operate at layer 3 while switches operate at layer 2.