Trunk配置实例
如图,两台交换机SW1和SW2各划分了三个VLAN,端口配置如下:
VLAN 1: F0/1 - F0/3: VLAN 2: F0/4 - F0/10 VLAN 3: F0/11 - F0/23
两台交换机的配置类似,现在以SW1为例,介绍Trunk配置与验证的过程
1.在交换机上添加vlan
sw1(config)#vlan 2
sw1(config-vlan)#exit
sw1(config)#vlan 3
sw1(config-vlan)#exit
2.将接口添加到相应的VLAN中,命令如下
sw1(config)#interface range f0/4 - 10
sw1(config-if)#switchport mode access
sw1(config-if)#switchport access vlan 2
sw1(config)interface range f0/11 - 23
sw1(config-if)#switchport mode access
sw1(config-if)#switchport access vlan 3
3.配置交换机之间互联的端口为Trunk模式,命令如下
sw1(config)#interface f0/24
sw1(config-if)switchport mode trunk
4.在另一台交换机上执行类似的配置,配置完成后,使用show命令进行验证,命令如下。
SW1#show int fa0/24 switchport
Name: Fa0/24
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
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
SW1#show int fa0/24 switchport
Name: Fa0/24
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
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: 1,3-1005
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
从上面show int fa0/24 switchport 命令的输出可以看出,Trunk中已经移除了VLAN2。
Trunk的排错
VLAN中常见故障是设备不能跨越Trunk链路而建立连接。为了能够对Trunk接口的故障进行排错,需要验证下列配置是否正确。
1.接口模式
要确保至少一则的链路的Trunk模式应当是Trunk或desirable。通过使用命令 show interfaces trunk 可以验证接口的Trunk配置。
2。封装类型
确保链路两端的Trunk的封装类型兼容