STP RSTP MSTP PVST+学

Default STP Configuration

自定义STP 配置

Feature                                                                Default  Value

功能                                                                    缺省值

Enable state                                                         STP enable for all VLANs                                    

开启状态                                                            所有VLAN默认开启STP

Bridge priority                                                     32768

网桥优先级

STP port priority (configurable on                      128

a per-port basis--used on LAN ports

configured as Layer2 access ports)

基于2层访问端口的每端口优先级

STP prot cost (configurable on a per-                 Gigabit Ethernet :4

port basis--used on LAN ports                           Fast Ethernet :19

configured as Layer 2 access ports)                     Ethernet : 100

基于2层访问端口的每端口成本

STP VLAN port priority(configurble on            128

a per-VLAN basis--used on LAN ports

configured as Layer2 trunk ports)

基于2层trunk端口的每VLAN优先级

STP VLAN port cost (configurable on a              Gigabit Ethernet :4

per-VLAN basis--used on LAN ports                  Fast Ethernet :19

configured as Layer 2 trunk ports)                        Ethernet :100

基于2层trunk端口的每VLAN优先级

Hello  time                                                               2 seconds

hello 时间                                                                2 秒

Forward delay time                                                  15 seconds

转发延时                                                                  15 秒

Maximum aging time                                                20 seconds

最大生存时间                                                         20 秒

Mode                                                                        PVST

模式                                                                         每VLAN 生成树

Enabling   STP  

开启 STP

STP is enabled by default on VLAN 1 and on all newly created VLANs.

STP 在VLAN1和所有被创建的VLAN 上自动开启。

You can eanble STP on a per-VLAN basis.The switch maintains a separate instance of  STP for

each VLAN (except on VLANs on  which you disable STP).

可以基于VLAN 开启STP。基于每个VLAN实例维护STP。（除非你在VLAN上关闭STP）

To eanble STP on a per-VLAN basis, perform this task:

下面的命令开启基于每VLAN 的STP。

Router (config)#spanning-tree vlan vlan_id

Enable STP on a per-vlan basis. The vlan_id value can be 1 through 4096,except reserved VLANs

在1到4096上开启除保留VLAN以外的每VLAN STP。

Router(config)#default spanning-tree vlan vlan_id

Reverts all STP parameters to default values for the specified VLAN.

在选择的VLAN上恢复所有STP自定义值

Router(config)#no spanning-tree vlan vlan_id

Disable STP on the specified VLAN; see the following Cautions for information regarding this command.

关闭指定VLAN上的STP。注意查看命令后显示的警告信息。

Router(config)#end

exits configuration mode

退出配置模式

Router# show spanning-tree vlan vlan_id

Verifies that STP is enabled.

验证STP开启

IEEE 802.1w    RSTP

替换端口  备份端口

丢弃状态 学习状态 转发状态

快速版本的PVST+    RPVST+  是RSTP实现的按VLAN版本

RSTP 只对 BPDU 的格式做了少量的变更。

对BPDU 中的端口状态和角色进行编码

处理提议和协定机制

RSTP BPDU 的类型是2，版本是2

7  拓朴变更

6 提议

54      00 未知  01 替代/备份  10 根 11 指定

3 学习

2 转发

1 协定

0 变更ACK

边缘端口   链路类型

交换机能够从端口的双工模式中获得链路类型，全双工模式的端口就是点到点的链路。