拓扑一 结果：NO
默认auto（被动）模式
Switch>show interfaces fastEthernet 0/1 switchPort Name: Fa0/1 Switchport: Enabled Administrative Mode: dynamic auto Operational Mode: static access Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: native Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk private VLANs: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL Protected: false
Switch>show interfaces trunk
Switch>
拓扑二 结果：YES
修改2端主动模式（desirable）
Switch>en Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode dynamic desirable Switch(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
Switch#show interfaces trunk
Port Mode Encapsulation Status Native vlan
Fa0/1 desirable n-802.1q trunking 1
Port Vlans allowed on trunk
Fa0/1 1-1005
Port Vlans allowed and active in management domain
Fa0/1 1
Port Vlans in spanning tree forwarding state and not pruned
Fa0/1 1
拓扑三 结果：YES
修改一端主动模式（desirable）
Switch>en Switch#conf t Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode dynamic desirable %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
Switch#show interfaces trunk
Port Mode Encapsulation Status Native vlan
Fa0/1 desirable n-802.1q trunking 1
Port Vlans allowed on trunk
Fa0/1 1-1005
Port Vlans allowed and active in management domain
Fa0/1 1
Port Vlans in spanning tree forwarding state and not pruned
Fa0/1 1
拓扑四 结果：YES
修改一端 trunk
Switch>en Switch#conf Configuring from terminal, memory, or network [terminal]? conf t ?Must be "terminal", "memory" or "network" Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode trunk Switch(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up Switch#show interfaces trunk Port Mode Encapsulation Status Native vlan Fa0/1 on 802.1q trunking 1 Port Vlans allowed on trunk Fa0/1 1-1005 Port Vlans allowed and active in management domain Fa0/1 1 Port Vlans in spanning tree forwarding state and not pruned Fa0/1 1
默认auto，修改desirable
Switch>en Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode dynamic desirable Switch(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up Switch(config-if)#end Switch# %SYS-5-CONFIG_I: Configured from console by console Switch#show interfaces trunk Port Mode Encapsulation Status Native vlan Fa0/1 desirable n-802.1q trunking 1 Port Vlans allowed on trunk Fa0/1 1-1005 Port Vlans allowed and active in management domain Fa0/1 1 Port Vlans in spanning tree forwarding state and not
拓扑五 结果：NO
修改一端 access
Switch>en Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode access Switch(config-if)#end %SYS-5-CONFIG_I: Configured from console by console s % Ambiguous command: "s" Switch#show interfaces trunk
默认auto，修改desirable
Switch>en Switch#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface fastEthernet 0/1 Switch(config-if)#switchport mode dynamic desirable Switch(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up Switch(config-if)#end Switch# %SYS-5-CONFIG_I: Configured from console by console Switch#show interfaces trunk
拓扑六 结果：YES