Читать книгу CCNP Enterprise Certification Study Guide: Implementing and Operating Cisco Enterprise Network Core Technologies - Ben Piper, David Higby Clinton - Страница 68

In RSTP, a port can have one of three states: learning, forwarding, or discarding. A port eventually settles into either a forwarding or discarding state. The learning state is transitory and only occurs when RSTP is in the process of determining which ports to block.

 Discarding—The port processes incoming BPDUs but doesn't send them. IOS lists a port in the discarding state as BLK or blocking. This is the initial state for all ports.

 Learning—The port sends and receives BPDUs but doesn't forward data traffic. The switch looks at ingressing Ethernet frames and adds the source MAC addresses to its MAC address table.

 Forwarding—Sends and receives BPDUs, and it also passes normal user and control plane traffic.