Mcadu_Blog'S

一、交换机SW1配置：

Switch1(config)#vlan 20
Switch1(config)#vlan 30

Switch1(config)#interface fastEthernet 0/1
Switch1(config-if)#switchport mode access
Switch1(config-if)#switchport access vlan 20

Switch1(config)#interface fastEthernet 0/2
Switch1(config-if)#switchport mode access
Switch1(config-if)#switchport access vlan 30

Switch1#show vlan

VLAN Name                             Status    Ports
—- ——————————– ——— ——————————-
1    default                          active    Fa0/3, Fa0/4, Fa0/5, Fa0/6
                                                Fa0/7, Fa0/8, Fa0/9, Fa0/10
                                                Fa0/11, Fa0/12, Fa0/13, Fa0/14
                                                Fa0/15, Fa0/16, Fa0/17, Fa0/18
                                                Fa0/19, Fa0/20, Fa0/21, Fa0/22
                                                Fa0/23, Fa0/24
20   VLAN0020                         active    Fa0/1
30   VLAN0030                         active    Fa0/2
1002 fddi-default                     active  
1003 token-ring-default               active  
1004 fddinet-default                  active  
1005 trnet-default                    active  

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
—- —– ———- —– —— —— ——– —- ——– —— ——
1    enet  100001     1500  -      -      -        -    -        0      0
20   enet  100020     1500  -      -      -        -    -        0      0
30   enet  100030     1500  -      -      -        -    -        0      0
1002 enet  101002     1500  -      -      -        -    -        0      0
1003 enet  101003     1500  -      -      -        -    -        0      0
1004 enet  101004     1500  -      -      -        -    -        0      0
1005 enet  101005     1500  -      -      -        -    -        0      0

Switch1(config)#interface fastEthernet 0/24
Switch1(config-if)#switchport mode trunk     //2950交换机只能封装dot1q ,所以无须键入switchport trunk encanpsulation dotiq
Switch1#show vlan

VLAN Name                             Status    Ports
—- ——————————– ——— ——————————-
1    default                          active    Fa0/3, Fa0/4, Fa0/5, Fa0/6
                                                Fa0/7, Fa0/8, Fa0/9, Fa0/10
                                                Fa0/11, Fa0/12, Fa0/13, Fa0/14
                                                Fa0/15, Fa0/16, Fa0/17, Fa0/18
                                                Fa0/19, Fa0/20, Fa0/21, Fa0/22
                                                Fa0/23
20   VLAN0020                         active    Fa0/1
30   VLAN0030                         active    Fa0/2
1002 fddi-default                     active  
1003 token-ring-default               active  
1004 fddinet-default                  active  
1005 trnet-default                    active  

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
—- —– ———- —– —— —— ——– —- ——– —— ——
1    enet  100001     1500  -      -      -        -    -        0      0
20   enet  100020     1500  -      -      -        -    -        0      0
30   enet  100030     1500  -      -      -        -    -        0      0
1002 enet  101002     1500  -      -      -        -    -        0      0
1003 enet  101003     1500  -      -      -        -    -        0      0
1004 enet  101004     1500  -      -      -        -    -        0      0
1005 enet  101005     1500  -      -      -        -    -        0      0

Switch1#show interfaces trunk
Port        Mode         Encapsulation  Status        Native vlan
Fa0/24      on           802.1q         trunking      1

Port        Vlans allowed on trunk
Fa0/24      1-1005

Port        Vlans allowed and active in management domain
Fa0/24      1,20,30,1002,1003,1004,1005

Port        Vlans in spanning tree forwarding state and not pruned
Fa0/24      1,20,30,1002,1003,1004,1005
Switch1(config)#interface fastEthernet 0/24
Switch1(config-if)#switchport native vlan 20
Switch1#show interfaces trunk
Port        Mode         Encapsulation  Status        Native vlan
Fa0/24      on           802.1q         trunking      20

Port        Vlans allowed on trunk
Fa0/24      1-1005

Port        Vlans allowed and active in management domain
Fa0/24      1,20,30,1002,1003,1004,1005

Port        Vlans in spanning tree forwarding state and not pruned
Fa0/24      1,20,30,1002,1003,1004,1005

 二、交换机SW2配置：

Switch2(config)#interface fastEthernet 0/24
Switch2(config-if)#switchport mode trunk

三、DTP

Cisco交换机之间的链路是否形成Trunk是可以自动协商的，这个协议称为DTP（Dynamic Trunk Protocol),DTP还可以协商Trunk链路的封装类型。