Module 4 Quiz Review

Refer to the exhibit. A network administrator is configuring inter-VLAN routing on a network. For now, only one VLAN is being used, but more will be added soon. What is the missing parameter that is shown as the highlighted question mark in the graphic?

• It identifies the subinterface.

• It identifies the VLAN number.

• It identifies the native VLAN number.

• It identifies the type of encapsulation that is used.

• It identifies the number of hosts that are allowed on the interface.

Answer explanation

The completed command would be encapsulation dot1q 7 . The encapsulation dot1q part of the command enables trunking and identifies the type of trunking to use. The 7 identifies the VLAN number.

Which two statements are correct with respect to SVI inter-VLAN routing? (Choose two.)

• Switching packets is faster with SVI.

• There is no need for a connection to a router.

• Virtual interfaces support subinterfaces.

• SVIs can be bundled into EtherChannels.

• SVIs eliminate the need for a default gateway in the hosts.

Answer explanation

The SVI inter-VLAN routing method is faster than other methods. The switch can route the existing VLANs without the need for a router.

Refer to the exhibit. What is the cause of the error that is displayed in the configuration of inter-VLAN routing on router CiscoVille?

• The gig0/0 interface does not support inter-VLAN routing.

• The no shutdown command has not been configured.

• The IP address on CiscoVille is incorrect.

• The encapsulation dot1Q 20 command has not been configured.​

Refer to the exhibit. A network administrator has configured router CiscoVille with the above commands to provide inter-VLAN routing. What command will be required on a switch that is connected to the Gi0/0 interface on router CiscoVille to allow inter-VLAN routing?​

• switchport mode access

• no switchport

• switchport mode trunk

• switchport mode dynamic desirable

Answer explanation

When they are configured for inter-VLAN routing, routers do not support the dynamic trunking protocol that is used by switches. For router-on-a-stick configurations to function, a connected switch must use the command switchport mode trunk .

A high school uses VLAN15 for the laboratory network and VLAN30 for the faculty network. What is required to enable communication between these two VLANs while using the router-on-a-stick approach?

• A multilayer switch is needed.

• A router with at least two LAN interfaces is needed.

• Two groups of switches are needed, each with ports that are configured for one VLAN.

• A switch with a port that is configured as a trunk is needed when connecting to the router.

Answer explanation

With router-on-a-stick, inter-VLAN routing is performed by a router with a single router interface that is connected to a switch port configured with trunk mode. Multiple subinterfaces, each configured for a VLAN, can be configured under the single physical router interface. Switches can have ports that are assigned to different VLANs, but communication between those VLANs requires routing function from the router. A multilayer switch is not used in a router-on-a-stick approach to inter-VLAN routing.

When routing a large number of VLANs, what are two disadvantages of using the router-on-a-stick inter-VLAN routing method rather than the multilayer switch inter-VLAN routing method? (Choose two.)

• Multiple SVIs are needed.

• A dedicated router is required.

• Router-on-a-stick requires subinterfaces to be configured on the same subnets.

• Router-on-a-stick requires multiple physical interfaces on a router.

• Multiple subinterfaces may impact the traffic flow speed.

Answer explanation

With the router-on-a-stick inter-VLAN routing method, a dedicated router is required. It only needs one physical interface on the router to route traffic among multiple VLANs, by using subinterfaces on one physical interface. On the other hand, since traffic of all VLANs will have to go through the same physical interfaces, the throughput will be impacted. Also, a multilayer switch can use multiple SVIs to perform inter-VLAN routing.

Refer to the exhibit. A network administrator is verifying the configuration of inter-VLAN routing. Users complain that PCs on different VLANs cannot communicate. Based on the output, what are two configuration errors on switch interface Gi1/1? (Choose two.)

• Gi1/1 is in the default VLAN.

• Voice VLAN is not assigned to Gi1/1.

• Gi1/1 is configured as trunk mode.

• Negotiation of trunking is turned on on Gi1/1.

• The trunking encapsulation protocol is configured wrong.

Refer to the exhibit. A network administrator is verifying the configuration of inter-VLAN routing. Users complain that PC2 cannot communicate with PC1. Based on the output, what is the possible cause of the problem?

• Gi0/0 is not configured as a trunk port.

• The command interface GigabitEthernet0/0.5 was entered incorrectly.

• There is no IP address configured on the interface Gi0/0.

• The no shutdown command is not entered on subinterfaces.

• The encapsulation dot1Q 5 command contains the wrong VLAN.

Answer explanation

In router-on-a-stick, the subinterface configuration should match the VLAN number in the encapsulation command, in this case, the command encapsulation dot1Q 10 should be used for VLAN 10. Since subinterfaces are used, there is no need to configure IP on the physical interface Gi0/0. The trunk mode is configured on the switch port that connects to the router. The subinterfaces are turned on when they are added.

Refer to the exhibit. A network administrator has configured router CiscoVille with the above commands to provide inter-VLAN routing. What type of port will be required on a switch that is connected to Gi0/0 on router CiscoVille to allow inter-VLAN routing?

• routed port

• access port

• trunk port

• SVI

Answer explanation

To allow a router-on-a-stick configuration to function, a switch must be connected to the router via a trunk port to carry the VLANs to be routed. An SVI would be used on a multilayer switch where the switch is performing inter-VLAN routing.

Refer to the exhibit. A network administrator is configuring RT1 for inter-VLAN routing. The switch is configured correctly and is functional. Host1, Host2, and Host3 cannot communicate with each other. Based on the router configuration, what is causing the problem?

• Interface Fa0/0 is missing IP address configuration information.

• IP addresses on the subinterfaces are incorrectly matched to the VLANs.

• Each subinterface of Fa0/0 needs separate no shutdown commands.

• Routers do not support 802.1Q encapsulation on subinterfaces.

Answer explanation

Since Host 1 (in VLAN 20) has the IP 172.18.1.10/27, the subinterface Fa0/0.1 should be configured with an IP address in the network 172.168.1.0/27. Similarly, Fa0/0.2 should be with an IP address in the network 172.168.1.64/27 and Fa0/0.3 should be with an IP address in the network 172.168.1.96/27.