What commands can be used to verify the trunking configuration of a router performing inter-VLAN routing? (Choose all that apply. Each correct answer is a complete solution.)
router# show trunk
router# show vlans
router# show vtp status
router# show ip interface brief
router# show ip route
The command show vlans verifies the trunking configuration of a router performing inter-VLAN routing. This command will indicate what subinterfaces are associated with what VLANs, the trunking protocol being used, and the IP addresses that the router is using on each of the VLANs. Below is sample output of the show vlans command:
The show ip route command can also be used to determine the correct configuration of inter-VLAN routing. If routing is configured correctly, there should be a route to each VLAN displayed in the output. If a route to a VLAN is missing, most likely the router is missing the command to assign an IP address to the VLAN in VLAN configuration mode. Below is output of the command on the same router as in the previous sample output, showing a route to both VLANs. If an IP address is not configured for a VLAN, a route to the VLAN will not be present.
The command show trunk is not a valid command to issue on a router. Routers do not understand trunking in the same way switches do. Routers must be configured with a unique subinterface representing each VLAN, mimicking how the router normally connects different network with physical interfaces.
The command show ip interface brief is not used to verify trunking on a router. This command is useful in identifying IP addresses assigned to interfaces, and the state of the interfaces. No VLAN or trunking information is included in the output.
The command show vtp status is not a valid command on a router. The router does not use or understand VTP.
Layer 2 Technologies
Configure and verify trunking