Cisco WS-X6K-SUP1A-PFC= Software Guide - Page 120

Understanding How Spanning Tree Protocols Work Chapter 8 Configuring Spanning Tree Figure 8-4 Port 2 in Listening State All segment frames Forwarding Station addresses Port 1 BPDUs Network management and data frames Filtering database System module Frame forwarding Data frames BPDUs Port 2 Network management frames S5693 Listening All segment frames BPDU and network management frames A port in the listening state performs as follows: • Discards frames received from the attached segment. • Discards frames switched from another port for forwarding. • Does not incorporate station location into its address database. (There is no learning at this point, so there is no address database update.) • Receives BPDUs and directs them to the system module. • Processes BPDUs received from the system module. • Receives and responds to network management messages. Learning State A port in the learning state prepares to participate in frame forwarding. The port enters the learning state from the listening state. Figure 8-5 shows a port in the learning state. A port in the learning state performs as follows: • Discards frames received from the attached segment. • Discards frames switched from another port for forwarding. • Incorporates station location into its address database. • Receives BPDUs and directs them to the system module. Catalyst 6000 Family Software Configuration Guide-Releases 6.3 and 6.4 8-8 78-13315-02