Spanning Tree
| Attribut | STP | PVST | PVST+ | RSTP | RPVST+ | MST |
|---|---|---|---|---|---|---|
| Algorithmus | Legacy ST | Legacy ST | Legac ST | Rapid ST | Rapid ST | Rapid ST |
| Standard | 802.1D-1998 | Cisco | Cisco | 802.1w, 802.1D-2004 | Cisco | 802.1s, 802.1Q-2003 |
| Instanzen | 1 | 1 pro VLAN | 1 pro VLAN | 1 | 1 pro VLAN | 1-mehre |
| Trunk | - | ISL | 802.1Q, ISL | - | 802.1Q, ISL | 802.1Q, ISL |
Link-Kosten
| Speed | Kosten |
|---|---|
| 4 Mbps | 250 |
| 10 Mbps | 100 |
| 16 Mbps | 62 |
| 45 Mbps | 39 |
| 100 Mbps | 19 |
| 155 Mbps | 14 |
| 622 Mbps | 6 |
| 1 Gbps | 4 |
| 10 Gbps | 2 |
| 20+ Gbps | 1 |
Priorität
- 0 (Notfall Wert für neu Root-Bridge)
- 4096 (tiefester Wert bei Normaler Konfiguration)
- 8192
- 12288
- 20480
- 24576
- 28672
- 32768 (Standard Wert)
- 36864
- 40960
- 45056
- 49152
- 53248
- 57344
- 61440 (Maximal Wert)
Bridge-ID
Die Bridge-ID ist wie folgt Zusammengesetz: 4 Bit Priorität + 12 System ID (VLAN) + 48 Bit MAC-Adresse
Pfadentscheidung
- Bridge mit der tiefesten ID wird Root-Bridge.
- Switche mit den tieferen Pfadkosten zur Root-Bridge.
- Switche mit der tieferen ID.
- Tiefste Portnummer.
Konfiguration RSTP, RPVST+
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Switch 1
SW1#conf t
SW1(config)spanning-tree mode rapid-pvst
SW1(config)spanning-tree vlan 1 priority 4096
SW1(config)interface range FastEthernet0/1-24
SW1(config-if)spanning-tree portfast
SW1(config-if)spanning-tree guard loop
SW1(config-if)spanning-tree guard root
SW1(config-if)spanning-tree bpduguard enable
SW1(config-if)spanning-tree bpdufilter enable
SW1(config-if)description Client
SW1(config-if)interface range GigabitEthernet0/1-2
SW1(config-if)no spanning-tree portfast
SW1(config-if)spanning-tree guard root
SW1(config-if)description Uplink
SW1(config-if)do wr
Switch 2
SW2#conf t
SW2(config)spanning-tree mode rapid-pvst
SW2(config)spanning-tree vlan 1 priority 32768
SW2(config)interface range FastEthernet0/1-24
SW2(config-if)spanning-tree portfast
SW2(config-if)spanning-tree guard loop
SW2(config-if)spanning-tree guard root
SW2(config-if)spanning-tree bpduguard enable
SW2(config-if)spanning-tree bpdufilter enable
SW2(config-if)description Client
SW2(config-if)interface range GigabitEthernet0/1-2
SW2(config-if)no spanning-tree portfast
SW2(config-if)description Uplink
SW2(config-if)do wr
Switch 3
SW3#conf t
SW3(config)spanning-tree mode rapid-pvst
SW3(config)spanning-tree vlan 1 priority 32768
SW3(config)interface range FastEthernet0/1-24
SW3(config-if)spanning-tree portfast
SW3(config-if)spanning-tree guard loop
SW3(config-if)spanning-tree guard root
SW3(config-if)spanning-tree bpduguard enable
SW3(config-if)spanning-tree bpdufilter enable
SW3(config-if)description Client
SW3(config-if)interface range GigabitEthernet0/1-2
SW3(config-if)no spanning-tree portfast
SW3(config-if)description Uplink
SW3(config-if)do wr
Troubelshooting
show spanning-tree [summary | detail | root]
show spanning-tree [interface | vlan]
show spanning-tree mst [...]