ch.4
A small college uses VLAN 10 for the classroom network and VLAN 20 for the office network. What is needed to enable communication between these two VLANs while using legacy inter-VLAN routing?
- A router with at least two LAN interfaces should be used. - Topic 4.1.0 - With legacy inter-VLAN routing, different physical router interfaces are connected to different physical switch ports. The switch ports that connect to the router are in access mode, each belonging to a different VLAN. Switches can have ports that are assigned to different VLANs, but communication between VLANs requires routing function from the router.
An administrator was troubleshooting a router-on-a-stick topology and concluded that the problem was related to the configuration of VLANs on the router subinterfaces. Which two commands can the administrator use in the router to identify the problem? (Choose two.)
- Show ip interface and show running-config. -Topic 4.4.0 - The show ip interface and show running-config commands can be useful in troubleshooting routing issues like wrong VLAN IDs that are assigned to subinterfaces. The show controllers and show ip protocols commands do not display any information about VLANs. The show vlan command is not useful to show information about the router subinterfaces.
what are 3 options for inter vlan routing?
- legacy inter-VLAN routing- does not scale well - router-on-a-stick- acceptable for small to medium sized network - layer 3 switches using SVI's - most scalable solution for medium to large organizations
what do vlans need to be reachable by other layer 3 devices?
- they need to be advertised using static or dynamic routing. - achieved by creating a routed port. - you can use the no switchport interface configuration command to create routed port.
A PC is to access a web server on another network. Which inter-VLAN method will provide the highest bandwidth at Layer 3 and also provide a default gateway for the PC?
A multilayer switch with routing enabled. - Topic 4.3.0 - A router-on-a-stick design is the same as having a trunked interface between the router and the switch. This design works, but does not scale well because all VLANs must traverse the one connection between the router and the switch. Multiple physical interfaces on the router would be faster than the router-on-a-stick design, but a router has a limited number of physical interfaces. Layer 3 switches with routing enabled have more Ethernet ports as well as the ability to route.
What operational mode should be used on a switch port to connect it to a router for router-on-a-stick inter-VLAN routing?
Trunk. - Topic 4.2.0 - Routers do not support Dynamic Trunking Protocol, and access mode is used to connect hosts.
Inter-VLAN Routing
a process for forwarding network traffic from one VLAN to another
Which sentence correctly describes the SVI inter-VLAN routing method?
an SVI is needed for each VLAN. - Topic 4.1.0 - In order to create SVI inter-VLAN routing on a Layer 3 switch, the VLAN must exist in the database and the SVI must be explicitly created. The only exception is VLAN1, which is created by default.
this command requires the subinterface to respond to 802.1q encapsulated traffic from the specified vlan
encapsulation dot1q vlan_id
- only requires one physical ethernet interface route traffic between multiple VLANS on a network. - configured using subinterfaces and are virtual interfaces configured on a router. - exha subinterface has its independent ip address and vlan
router on a stick
you are troubleshooting an inter vlan issue on a router and need to verify the status IP address of all interfaces in a condensed format. which inter vlan troubleshooting command would you use to do this?
show IP interface brief command is used to verify the status and IP address of all interfaces in a condensed format.
you are troubleshooting an inter vlan issue on a router and need to verify that the subinterfaces are in the routing table. which inter vlan routing troubleshooting command would you use to do this?
show io route
you are troubleshooting an inter vlan issue on a switch and need to check the lists of vlans and their assigned ports. which inter vlan troubleshooting command would you use to do this?
show vlan command would display the list of VLANS and their assigned ports.
A network administrator enters the following command sequence on a Cisco 3560 switch. What is the purpose of these commands? Switch(config)# interface gigabitethernet 0/1Switch(config-if)# no switchport
To make the Gi0/1 port a routed port. -By default, the physical ports on a 3560 switch are Layer 2 interfaces. To make them routed ports, the interface command no switchport should be used. The other options do not describe the purpose of this command.
