CSC 2773: VLAN & TRUNK

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What command is used to create a VLAN with a valid ID number?

Switch# vlan vlan-id

Switch(config)# create vlan vlan-id

Switch(config)# vlan vlan-id (correct)

Switch(config)# define vlan vlan-id

What is the first step to assign a port to a VLAN after creating the VLAN?

Switch(config)# vlan vlan-id

Switch(config)# configure terminal (correct)

Switch(config-if)# assign port

Switch(config-if)# access control configuration

Which command sets the port to access mode in VLAN configuration?

Switch(config-if)# switchport access mode

Switch(config-if)# switchport mode access (correct)

Switch(config-if)# set access port

Switch(config-if)# port mode access

What happens if a VLAN is created but not named?

The VLAN will have a default name Signup and view all the answers

In the command 'Switch(config-if)# switchport access vlan vlan-id', what does 'vlan-id' represent?

The ID number of the VLAN to which the port will be assigned Signup and view all the answers

What is the primary advantage of segmenting a LAN using VLANs?

Reduces the number of broadcast domains Signup and view all the answers

Which type of VLAN carries traffic for management purposes?

Management VLAN Signup and view all the answers

Which VLAN is known as VLAN 1, where all switch ports are members by default?

Default VLAN Signup and view all the answers

What is one of the features of VLANs in terms of user communication?

Users in the same VLAN are unaware of other VLANs Signup and view all the answers

What benefit do smaller broadcast domains provide in a VLAN setup?

They allow for better security controls Signup and view all the answers

What must happen for packets to be exchanged between different VLANs?

Employ a router for inter-VLAN communication Signup and view all the answers

Where are VLAN details typically stored within the network device?

In the vlan.dat file Signup and view all the answers

Why is VLAN partitioning considered a logical division rather than a physical one?

It can create multiple isolated segments on the same physical hardware Signup and view all the answers

What is the primary purpose of a VLAN trunk?

To carry traffic for multiple VLANs between switches Signup and view all the answers

Which command is used to display VLAN information in a concise format?

show vlan brief Signup and view all the answers

How does a switch handle a broadcast frame received on a port?

It forwards the frame out all ports except the originating port Signup and view all the answers

Which protocol does Cisco IOS support for VLAN trunking?

IEEE 802.1Q Signup and view all the answers

What is the primary purpose of tagging Ethernet frames with VLAN information?

To properly transmit multiple VLAN frames through a trunk link. Signup and view all the answers

What command would you use to display information about a specific VLAN using its ID?

show vlan id number.vlan-id Signup and view all the answers

Which VLAN is typically designated as the native VLAN on Cisco switches?

VLAN 1 Signup and view all the answers

Which statement correctly describes the role of VLANs in a network?

VLANs are used to manage traffic by segmenting broadcast domains Signup and view all the answers

What happens to untagged frames received on a native VLAN?

They are placed in the native VLAN without tagging. Signup and view all the answers

What happens when a device on VLAN 10 sends a broadcast frame?

Only devices in VLAN 10 receive the frame Signup and view all the answers

What is a unique characteristic of VLANs regarding broadcast domains?

Each VLAN represents an isolated network segment Signup and view all the answers

In the context of VLANs, what is a trunk port primarily used for?

To carry traffic from multiple VLANs between switches. Signup and view all the answers

What occurs if there are no ports associated with the native VLAN and an untagged frame is received?

The untagged frame is dropped. Signup and view all the answers

What is a characteristic of access ports in a VLAN configuration?

They belong to only one VLAN and transmit untagged frames. Signup and view all the answers

What process must occur before an Ethernet frame can be forwarded across a trunk link?

The frame must be tagged with its VLAN information. Signup and view all the answers

Which statement is true regarding the IEEE 802.1Q protocol?

It defines the structure of the VLAN tagging header. Signup and view all the answers

What is the function of the native VLAN in an 802.1Q trunk?

To accommodate untagged traffic Signup and view all the answers

Which command is used to assign the native VLAN ID on a physical interface in the switch configuration?

Switch(config-if)#dot1q native vlan vlan-id Signup and view all the answers

What role does a Layer 3 device play in inter-VLAN communication?

It provides connectivity between different VLANs. Signup and view all the answers

Which of the following is a requirement for configuring inter-VLAN routing?

Configuring subinterfaces on the router Signup and view all the answers

What is the purpose of configuring a switch interface as an 802.1Q trunk link?

To allow multiple VLANs to traverse the same link Signup and view all the answers

What minimum speed is recommended for the router interface when setting up inter-VLAN routing?

100 Mbps Signup and view all the answers

What is the main purpose of VTP in managing VLANs?

To automate VLAN configuration updates and maintain consistency Signup and view all the answers

What command is used to assign an IP address to a subinterface in a router for inter-VLAN routing?

Router(config-if)#ip address [IP Address] [Subnet Mask] Signup and view all the answers

Which of the following is NOT a step required to configure inter-VLAN routing?

Assign an IP address to the router interface Signup and view all the answers

In VTP, what happens when the configuration revision number is returned to zero?

The VLAN configuration history is cleared Signup and view all the answers

Which technology allows multiple logical pathways through a single physical router interface?

Subinterfaces Signup and view all the answers

Which VTP mode allows a switch to create, modify, and delete VLANs for the entire domain?

Server mode Signup and view all the answers

Which command would you use to verify the functionality of inter-VLAN routing?

Router#show ip interfaces brief Signup and view all the answers

What is the default version of VTP and is it compatible with the second version?

Version 1, not compatible with Version 2 Signup and view all the answers

What type of VTP messages are sent every 5 minutes or during a change in the VLAN database?

Summary advertisements Signup and view all the answers

Which command indicates that a router interface should actively participate in routing?

Router(config-if)#no shutdown Signup and view all the answers

Study Notes

LAN Technologies

CSC 2773 course covers LAN technologies.
Topics include LAN technologies, VLANs, 802.1Q Frame Tagging, and VTP.

VLAN Definitions

VLANs partition Layer 2 networks logically, independent of physical location.
Users on different floors can be in the same VLAN.
VLANs are broadcast domains spanning multiple physical LAN segments.
VLANs are mutually isolated, with packets passing between them only via routers.
Hosts within a VLAN are unaware of other VLANs' existence.

VLAN Benefits

Smaller Broadcast Domains: Fewer broadcast domains reduce network traffic.
Improved Security: Communication is limited to devices within the same VLAN.
Improved IT Efficiency: VLANs group devices with similar needs.
Reduced Cost: One switch can support multiple VLAN groups.
Better Performance: Reduced traffic improves bandwidth.
Simpler Management: Grouping similar devices simplifies network management.

Types of VLANs

Default VLAN (VLAN 1): All switch ports are members by default.
Data VLAN: Created for specific user groups or devices. Carries user-generated traffic.
Native VLAN: Carries untagged traffic, typically VLAN 1, which is exchanged between STP-enabled switches.
Management VLAN: Carries network management traffic (SSH, SNMP, Syslog). VLAN 1 is the default management VLAN.

Creating a VLAN

VLANs are created in global configuration mode.
Enter global configuration mode (Switch# configure terminal)
Create a VLAN with a valid ID (Switch(config)# vlan <vlan_id>).
Give the VLAN a name (Switch(config-vlan)# name <vlan_name>).
Exit VLAN configuration mode (Switch(config-vlan)# end).

Assigning Ports to VLANs

Assign ports to VLANs in interface configuration mode.
Enter interface configuration mode (Switch(config)# interface <interface_id>).
Set the port to access mode (Switch(config-if)# switchport mode access).
Assign the port to a VLAN (Switch(config-if)# switchport access vlan <vlan_id>).

Verifying VLANs

Use commands like show vlan, show vlan brief, show vlan id <vlan_id>, show vlan name <vlan_name> to verify VLAN information.

Packet Tracer

A Cisco Packet Tracer exercise demonstrates observation of broadcast traffic in a VLAN.

802.1Q Frame Tagging/Trunk

Frame tagging adds VLAN identification headers to frames for transmission on trunk links.
Used to transmit multiple VLAN frames through trunk links.
IEEE 802.1Q defines the frame tagging structure.
Switches add VLAN tags to frames after the source MAC address.

Native VLANs and 802.1Q Tagging

Control traffic on the native VLAN (typically VLAN 1) should not be tagged.
Frames received untagged remain untagged and are placed in the native VLAN.

Packet Tracer - Investigating a VLAN Implementation

A Packet Tracer exercise helps students investigate VLAN implementation.

Trunking and Inter-VLAN Routing (Trunks Ports)

Trunks: Point-to-point links carrying multiple VLANs, frequently used between switches.
802.1Q: A common tagging protocol for trunking links, to ensure proper handling/identification of VLAN Traffic/information between switches.
Subinterfaces: Logical subdivisions of a physical interface for each VLAN.

Inter-VLAN Routing

Enables communication between different VLANs.
A Layer 3 device (e.g., router) provides inter-VLAN connectivity.
Subinterfaces on the router provide separate IP addresses for each VLAN's traffic, routing traffic through routers via physical interconnections.

VTP (VLAN Trunking Protocol)

VTP automates VLAN configuration across a network. Prevents inconsistencies when configuring numerous VLANs on numerous switches.
VTP modes include server, client, and transparent.
Version 1 and 2 (version 2 newer/more compatible) are available, ensuring interoperability.
The VLAN Database uses a revision number to track changes across switches for accurate, up-to-date configuration.
VTP uses summary and subset advertisements, and requests, in order to update numerous switches. Essentially, these messages exchange data to confirm and update VLAN configurations in numerous switches.

Summary and Exercise

VLANs group hosts logically, despite physical separation.
Switches use frame tagging to identify VLANs.
Layer 3 devices (routers) route traffic between VLANs.
Subinterfaces allow routers to support multiple VLANs.
VTP manages VLAN configurations centrally.
Exercises help students understand and implement VLAN configurations.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores key concepts in LAN technologies covered in the CSC 2773 course. Topics include VLANs, 802.1Q Frame Tagging, and the benefits of using VLANs in network management. Test your knowledge and understanding of how VLANs improve network efficiency and security.