Section 9. Implementing VLANs and Trunks Flashcards
Q1-What are VLANs?
VLANs are broadcast domains in a Layer 2 network.
Each VLAN is like a distinct virtual bridge within the switch. Each virtual bridge you create in a switch defines a broadcast domain. By default, traffic from one VLAN cannot pass to another VLAN. Each of the users in a VLAN would also be in the same IP subnet. By default, each access port can belong to only one data VLAN.
Q2-What are the six characteristics of a typical VLAN setup?
Six characteristics of a typical VLAN setup are as follows:
Each logical VLAN is like a separate physical bridge.
For different VLANs to communicate with each other, traffic must be forwarded through a router or Layer 3 switch.
Each VLAN is considered to be a separate logical network.
VLANs can span multiple switches.
Each VLAN is a separate broadcast domain.
VLANs can enhance security by logically segmenting a network.
Q3-For VLANs to communicate with each other, what network component is needed?
A router or Layer 3 switch is needed for inter-VLAN communication. It is important to think of a VLAN as a distinct virtual bridge in a switch, with is its own IP subnet and broadcast domain. A network device cannot communicate from one IP subnet to another without a router. The same is true for a VLAN; you cannot communicate from one VLAN to another without a router-capable device.
Q4-What is VLAN membership?
VLAN membership describes which VLAN a port on a switch is assigned.
Q5-What are the three ways that inter-VLAN communication can be established?
The three ways that inter-VLAN communication can be established are as follows:
Router on a stick: Involves a single connection, called a trunk link, from the switch to a router. The trunk link uses a trunking protocol to differentiate between VLANs.
Router with a separate interface in each VLAN.
Layer 3 switch.
Q6-What are two methods to assign a port to a VLAN?
The two methods to assign a port to a VLAN are as follows:
Statically: Statically assigning a port to a VLAN is a manual process performed by the administrator.
Dynamically: VLAN Membership Policy Server (VMPS) allows you to define VLAN membership through the MAC address. Security products such as Cisco ISE allow you to set ports on VLANs based on the type of endpoint that connects to the port.
Q7-What are trunk links?
Trunk links allow the switch to carry multiple VLANs across a single link.
By default, each port on a switch belongs to VLAN 1. For devices that are in a VLAN (that spans multiple switches) to talk to other devices in the same VLAN, you must use trunking or have a dedicated port for each VLAN.
Trunk links encapsulate frames using a Layer 2 protocol. This encapsulation contains information for a switch to distinguish traffic from different VLANs and to deliver frames to the proper VLANs. The Catalyst 2960 supports 802.1Q as its trunking protocol.
Q8-Describe 802.1Q tagging.
IEEE 802.1Q tagging provides an industry-standard method of identifying frames that belong to a particular VLAN. 802.1Q does this by using an internal tag that modifies the existing Ethernet frame with the VLAN identification.
Q9-In 802.1Q, what is the native VLAN?
The native VLAN is VLAN1 by default. 802.1Q does not tag the native VLAN across trunk links.
Q10-What IOS commands assign interface g0/1 to VLAN 10 and interface g0/2 to VLAN 20?
From global configuration mode, the IOS commands that assign interface g0/1 to VLAN 10 and interface g0/2 to VLAN 20 are as follows:
Cat2960(config)# int g0/1
Cat2960(config-if)# switchport access vlan 10
Cat2960(config-if)# int g0/2
Cat2960(config-if)# switchport access vlan 20
Q11-As a network administrator, you want to add gigabit interfaces 1 through 12 to VLAN 10 on your Catalyst 2960 switch. How do you statically assign these ports to VLAN 10?
To configure a range of ports to a VLAN, enter the range command. The following commands from global configuration mode assign ports 1–12 to VLAN 10:
Cat2960(config)# interface range g 0/1 - 12
Cat2960(config-if-range)# switchport mode access
Cat2960(config-if-range)# switchport access vlan 10
Q12-Configure a Catalyst 2960 switch with VLAN number 10 and name the VLAN “Accounting.”
To configure a VLAN on a Catalyst 2960 switch, first ensure that the switch is in VTP server or transparent mode. When the switch is in one of these modes, the vlan vlan-id global configuration command adds a VLAN. The vlan-id can be a number from 2 to 1001 for normal-range VLANs and 1006 to 4094 for extended VLANs.
The following walks you through the solution configuration:
Switch(config)# vlan 10
Switch(config-vlan)# name Accounting
Q13-As a network administrator, you want to create two VLANs, one named Admin and the other named Sales. What commands will create the two VLANs using VLAN ID 10 for the Admin VLAN and VLAN ID 20 for the Sales VLAN?
Issue the following commands from global configuration mode to create the two VLANs: Cat2960(config)# vlan 10 Cat2960(config-vlan)# name Admin Cat2960(config-vlan)# vlan 20 Cat2960(config-vlan)# name Sales
Q14-What are normal-range VLANs?
Normal-range VLANs are VLANs with VLAN IDs from 1 to 1005.
If the switch is in VTP server or transparent mode, you can add, modify, or remove configuration for VLANs 2 to 1001 in the VLAN database. VLAN IDs 1 and 1002–1005 are automatically created and cannot be removed. VLAN ID 1 is reserved as the default VLAN and VLAN IDs 1002–1005 are reserved for Token Ring and FDDI.
Q15-What are extended-range VLANs?
Extended-range VLANs are VLANs with VLAN IDs from 1006 to 4094. Extended-range VLANs can only be configured if the switch is in VTP transparent mode with the appropriate IOS licensing installed. Extended-range VLAN configurations are not stored in the VLAN database but are stored in the switch running the configuration file.
