該方式下， 首先將L2與L3的內部接口作成以太通道，然后，在L3上創建一個虛擬的通道接口，在該接口下開子接口為各個VLAN提供三層路由功能。 在廣西城域網工程中，所有的4006交換機都是采用的這種方式。關于以太通道的介紹見上文。 配置步驟：（以下假設L3模去是插在第二槽上，且使用缺省的channel協議） ① L2：set port channel mod/ports 配置GE端口。 Cat4000> (enable) set port channel 2/1-2 mode on Ports 2/1-2 channel mode set to on. Cat4000> (enable) ②指定同一channel的端口為相同VLAN。 Cat4000> (enable) set vlan 1 2/1-2 <---端口2/1-2必須屬于同一VLAN VLAN Mod/Ports ---- ----------------------- 1 2/1-4,2/6-48 3/1-6 Cat4000> (enable)
③用 set trunk mod_num/port_num 打開Trunk功能并且指定封裝類型 Cat4000> (enable) set trunk 2/1 on dot1Q 1-10 <----只需要在其中一個端口指定trunk即可
Port(s) 2/1 trunk mode set to on Port(s) 2/1 trunk type set to dot1Q 1-10 Cat4000> (enable) ④利用 session mod_num 進入L3模塊 Cat4000> (enable) session 2
Trying Router... Connected to Router. Escape character is /Q^]'. router>
重復以上步驟直到將所有的VLAN都封裝完畢。 ⑧ 利用 native要害字封裝一個本地VLAN的子接口。需要為Trunk干道來產生一個本地VLAN子接口。注重，該native要求與L2的native vlan號相同 router(config)# interface port-channel channel_number.vlan_id router(config-subif)# encapsulation dot1Q vlan_id native <-------native指明此接口為本地VLAN接口 router(config-subif)# ip address ip_address subnet_mask router(config-subif)# exit 以下是該方式的一個完整示例： L2：（采用PAgP協議） Set vlan 1 2/1-2 set port channel 2/1-2 mode on set trunk 2/1 on dot1q 1-1005 set trunk 2/2 on dot1q 1-1005 L3： version 12.0 no service pad service timestamps debug datetime msec localtime show-timezone service timestamps log datetime msec localtime show-timezone service passWord-encryption ! hostname M-4006R-NN ! boot system Flash bootflash:cat4232-in-mz.120-18.W5.22b.bin enable secret 5 ! interface Loopback0 ip address no ip directed-broadcast ! interface Port-channel1 no ip address no ip directed-broadcast hold-queue 300 in ! interface Port-channel1.1 description manage-vlan encapsulation dot1Q 1 native no ip directed-broadcast ! interface Port-channel1.2 description local Management encapsulation dot1Q 2 no ip directed-broadcast ! interface Port-channel1.76 description uplink to encapsulation dot1Q 76 ip address XXXX no ip directed-broadcast ! interface Port-channel1.201 description PPPoE test 2002.8.1 encapsulation dot1Q 201 ip address 192.168.1.2 255.255.255.0 no ip directed-broadcast ! interface FastEthernet1 no ip address no ip directed-broadcast shutdown ! interface GigabitEthernet1 no ip address no ip directed-broadcast shutdown ! interface GigabitEthernet2 no ip address no ip directed-broadcast shutdown ! interface GigabitEthernet3 no ip address no ip directed-broadcast no negotiation auto channel-group 1 ! interface GigabitEthernet4 no ip address no ip directed-broadcast no negotiation auto channel-group 1 ! ip classless ip route 0.0.0.0 0.0.0.0 end
