0903 配置STP.ppt

配置STP 目标 通过本章的学习，你将能做到以下内容: 能够在交换机端口和VLANs启用STP 掌握生成树根桥的配置、端口代价及优先级的配置 验证生成树的配置 启用STP 配置根桥 设置接口Cost 核实STP 核实STP (Cont.) 总结 你可以基于每VLAN启用生成树. 具有最低桥ID的交换机将会成为一个VLAN内生成树的根. 生成树根据端口代价来考虑是否将该端口置于转发状态，你可以分配一个更小的值来使它得到优先选择. 你可以使用多种SHOW命令来显示生成树的信息. ? 2003, Cisco Systems, Inc. All rights reserved. BCMSN 2.0—3-* ? 2003, Cisco Systems, Inc. All rights reserved. 2-* ? 2003, Cisco Systems, Inc. All rights reserved. ? 2003, Cisco Systems, Inc. All rights reserved. BCMSN 2.0—3-* Switch(config)#spanning-tree vlan 200 在特定VLAN上启用STP Switch(config)#spanning-tree vlan 200 priority 4096 降低生成树优先级，迫使该交换机成为根桥 Switch(config)#spanning-tree vlan 200 priority 8192 设置交换机的生成树优先级能够使该交换机成为次根桥 Switch(config-if)#spanning-tree cost 18 配置一个交换机的生成树端口代价 Switch(config-if)#spanning-tree vlan 200 cost 17 配置一个交换机特定VLAN的VLAN端口代价 ASW11#show spanning-tree vlan 200 VLAN0200 Spanning tree enabled protocol ieee Root ID Priority 49352 Address 0008.2199.2bc0 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 49352 (priority 49152 sys-id-ext 200) Address 0008.2199.2bc0 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 Uplinkfast enabled Interface Port ID Designated Port ID Name Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr ---------------- -------- --------- --- --------- -------------------- -------- Fa0/1 128.1 3019 LIS 0 49352 0008.2199.2bc0 128.1 Fa0/2 128.2 3019 LIS 0 49352 0008.2199.2bc0 128.2 Switch#show spanning-tree vlan vlan-id 显示交换机的配置信息 Switch#show spanning-tree bridge  Hello Max FwdVlan Bridge ID Time Age Dly Protocol---------------- --------------------------------- ----- --- --- --------VLAN0200