SW-1

SW-1# configure terminal

SW-1(config)# interface Ethernet0/0

SW-1(config-if)# switchport trunk allowed vlan 5,6

SW-1(config-if)# exit

SW-1(config)# interface Ethernet0/1

SW-1(config-if)# switchport trunk native vlan 77

SW-1(config-if)# end

SW-1# copy running-config startup-config

SW-2

SW-2# configure terminal

SW-2(config)# interface Ethernet0/1

SW-2(config-if)# switchport trunk native vlan 77

SW-2(config-if)# exit

SW-2(config)# interface Ethernet0/2

SW-2(config-if)# switchport trunk allowed vlan 6

SW-2(config-if)# end

SW-2# copy running-config startup-config

SW-3

SW-3# configure terminal

SW-3(config)# interface range Ethernet0/0 - 1

SW-3(config-if-range)# channel-group 34 mode active

SW-3(config-if-range)# end

SW-3# copy running-config startup-config

SW-4

SW-4# configure terminal

SW-4(config)# interface range Ethernet0/0 - 1

SW-4(config-if-range)# channel-group 34 mode passive

SW-4(config-if-range)# end

SW-4# copy running-config startup-config

Verification commands:

SW-1# show interfaces trunk

SW-2# show interfaces trunk

SW-3# show etherchannel summary

SW-4# show etherchannel summary

SW-3# show interfaces port-channel 34

SW-4# show interfaces port-channel 34

The command switchport trunk allowed vlan 5,6 replaces the default allowed-VLAN list on SW-1 Ethernet0/0 so that only VLANs 5 and 6 can cross that trunk. The same command with VLAN 6 restricts SW-2 Ethernet0/2 to VLAN 6. Cisco documents that all VLANs are permitted on a trunk by default and that switchport trunk allowed vlan vlan-list defines the permitted list. The native VLAN must match at both ends of an 802.1Q trunk, so VLAN 77 is configured on Ethernet0/1 of both SW-1 and SW-2.

For LACP, active initiates negotiation and passive only responds. Therefore, SW-3 must use channel-group 34 mode active, while SW-4 must use channel-group 34 mode passive. Cisco confirms that active-to-passive forms an EtherChannel, whereas passive-to-passive does not. Because the physical interfaces are already identically configured as trunks, no trunk commands should be replaced during channel creation. The channel-group command creates and binds the physical members to logical Port-Channel 34.