Cisco WS-C4003 Software Guide - Page 107

Chapter 7 Configuring Spanning Tree Understanding PVST+ and MISTP Modes Figure 7-7 Port 2 in Disabled State All segment frames Forwarding Station addresses Port 1 BPDUs Network management and data frames Filtering database System module Frame forwarding Data frames Port 2 Network management frames S5696 Disabled All segment frames A disabled port 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, so there is no address database update.) • Receives BPDUs but does not direct them to the system module. • Does not receive BPDUs for transmission from the system module. • Receives and responds to network management messages. Understanding PVST+ and MISTP Modes Catalyst 4000 family switches provide two proprietary spanning tree modes based on the IEEE 802.1D standard and one mode that is a combination of the two modes: • Per VLAN Spanning Tree (PVST+) • Multi-Instance Spanning Tree Protocol (MISTP) • MISTP-PVST+ (combination mode) An overview of each mode is provided in this section. Each mode is described in detail in these sections: • Using PVST+, page 7-12 • Using MISTP-PVST+ or MISTP, page 7-18 78-12647-02 Software Configuration Guide-Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4 7-11