DTP
拓扑:
实验步骤:
(1)交换机VLAN 划分,将端口加入相应VLAN
(2) DTP使用
sw0(config)#interface f0/3
sw0(config-if)#switchport mode dynamic desirable //期望对端是 trunk auto desirable时自动成为中继链路
sw1(config)#interface f0/3
sw1(config-if)#switchport mode dynamic auto
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state to up
sw1(config-if)#
调试
sw0(config)#do show inter tru
Port Mode Encapsulation Status Native vlan
Fa0/3 auto n-802.1q trunking 1
Port Vlans allowed on trunk
Fa0/3 1-1005
Port Vlans allowed and active in management domain
Fa0/3 1,2,3
Port Vlans in spanning tree forwarding state and not pruned
Fa0/3 none
sw0(config)#
#switchport mode access //永久非中继链路
#switchport mode dynamic auto //自动 对端trunk desirable时自动成为中继链路
#switchport mode trunk //永久中继链路
#switchport nonegotiate //永久中继链路,但禁止接口产生DTP帧,建立中继链路,就必须手工将领接接口配置为中继接口