LAB5:Spanning Tree Protocol (STP 802.1D)
一、实验目的 1、掌握标准生成树(STP)的应用及配置 二、实验内容 拓扑图: 需求: 1、确保PC和服务器间通信路径最短 (注:橙色端口为阻塞端口) 三、实验配置 配置: 1、查看生成树 SW1#show spanning-tree (查看生成树) VLAN0001 (VLAN1 的生成树实例) Spanning tree enabled protocol ieee (生成树的模式为802.1D标准生成树) Root ID Priority 32769 (指示生成树根的Root ID,SW1为根桥) Address 0004.9A8B.7C69 This bridge is the root (指示此交换机为Vlan1生成树的根) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec (生成树计时器) Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) (指示此交换机的BridgeID) Address 0004.9A8B.7C69 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 20 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Fa0/21 Desg FWD 19 128.21 P2p (端口角色、状态及端口优先级) Fa0/22 Desg FWD 19 128.22 P2p SW3#show spanning-tree (SW3为非根桥) VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address 0004.9A8B.7C69 Cost 19 Port 22(FastEthernet0/22) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 00E0.A39D.C5A3 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 20 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Fa0/22 Root FWD 19 128.22 P2p Fa0/24 Desg FWD 19 128.24 P2p Gi0/1 Altn BLK 4 128.25 P2p Gi0/2 Desg FWD 4 128.26 P2p 2、根据需求,应该让SW3为STP的Root最为合理 SW3(config)#spanning-tree vlan 1 root primary (修改SW3的VLAN1生成树实例为根桥) 验证: SW3#show spanning-tree VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 24577 Address 00E0.A39D.C5A3 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 24577 (priority 24576 sys-id-ext 1) Address 00E0.A39D.C5A3 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 20 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Fa0/22 Desg FWD 19 128.22 P2p Fa0/24 Desg FWD 19 128.24 P2p Gi0/1 Desg FWD 4 128.25 P2p Gi0/2 Desg FWD 4 128.26 P2p 四、应用场景 STP协议对用户是透明的。自动会选举出block端口,阻止环路。但我们一定注意STP选举有可能选择出的路径不是最优的。这时候我们就要调整STP参数。达到流量优化的目的