“Layer 3 access” or “routed access” is not a specific vendor feature — it's a design pattern: Each access switch (or stack) becomes a Layer 3 device, not just a Layer 2 island. End devices are still in VLANs, but the default gateway SVI lives on the access switch, not. Layer 3 interfaces forward packets to another device using static or dynamic routing protocols. You can configure a port as a Layer 2 interface or a Layer 3 interface. In one common topology, known as a “router on a stick” or a “one-armed router,” you connect a router to an access switch with connections to. In Figure 2-12, PC1, PC2, and PC3 are on three network segments, and SwitchC, SwitchD, and SwitchE are access switches for the three network segments, respectively. To enable SwitchA and SwitchB to communicate with each other and provide high link bandwidth, Layer 3 Eth-Trunk interfaces need to be. The goal is not to declare “Layer 2 bad, Layer 3 good,” but to give you a practical mental model: When should I stop stretching VLANs and start routing closer to the edge? 1.
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