配置3层交换机VLAN间通信

SW2

Switch>en
Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.

Switch(config)#hostname SW2
SW2(config)#vlan
SW2(config-vlan)#name caiwu
SW2(config-vlan)#vlan
SW2(config-vlan)#name it
SW2(config-vlan)#exit

SW2(config)#interface range fastEthernet /-

SW2(config-if-range)#switchport mode access 

SW2(config-if-range)#switchport access vlan 

SW2(config-if-range)#interface fastEthernet /

SW2(config-if)#switchport mode access 

SW2(config-if)#switchport access vlan
SW2(config-if)#exit

SW2(config)#do show vlan br

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
    default                          active    Fa0/, Fa0/, Fa0/, Fa0/
                                                Fa0/, Fa0/, Fa0/, Fa0/
                                                Fa0/, Fa0/, Fa0/, Fa0/
                                                Fa0/, Fa0/, Fa0/, Fa0/
                                                Fa0/, Fa0/, Fa0/, Fa0/
                                                Fa0/, Gig0/, Gig0/
    caiwu                            active    Fa0/, Fa0/
    it                               active    Fa0/
 fddi-default                     active
 token-ring-default               active
 fddinet-default                  active
 trnet-default                    active    

SW2(config)#interface gigabitEthernet /

SW2(config-if)#switchport mode trunk

SW1

Switch>en
Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.

Switch(config)#hostname SW1
SW1(config)#vlan
SW1(config-vlan)#name caiwu
SW1(config-vlan)#vlan
SW1(config-vlan)#name it
SW1(config-vlan)#exit

SW1(config)#interface gigabitEthernet /

SW1(config-if)#switchport mode trunk
Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode.

#三层交换机要打trunj，需要开启dot1q协议
SW1(config-if)#switchport trunk encapsulation dot1q 

SW1(config-if)#switchport mode trunk 

SW1(config-if)# exit

#进入VLAN2
SW1(config)#interface vlan 

%LINK--CHANGED: Interface Vlan2, changed state to up

%LINEPROTO--UPDOWN: Line protocol on Interface Vlan2, changed state to up

#配置VLAN2的网关
SW1(config-if)#ip add 192.168.2.254 255.255.255.0

SW1(config-if)#no shutdown 

SW1(config-if)#interface vlan 

%LINK--CHANGED: Interface Vlan3, changed state to up

%LINEPROTO--UPDOWN: Line protocol on Interface Vlan3, changed state to up

SW1(config-if)#ip add 192.168.2.254 255.255.255.0

SW1(config-if)#no shutdown 

SW1(config-if)#exit

SW1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/        unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
FastEthernet0/       unassigned      YES unset  down                  down
GigabitEthernet0/     unassigned      YES unset  up                    up
GigabitEthernet0/     unassigned      YES unset  down                  down
Vlan1                  unassigned      YES unset  administratively down down
Vlan2                  192.168.2.254   YES manual up                    up
Vlan3                  192.168.3.254   YES manual up                    up
SW1#

#开启三层交换的路由功能

SW1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.

SW1(config)#ip routing