Home > Articles > Cisco Certification > CCIE > Virtual LANs and VLAN Trunking

Virtual LANs and VLAN Trunking

Sample Chapter is provided courtesy of Cisco Press.
Date: Dec 25, 2009.

Chapter Information

"Do I Know This Already?" Quiz
Foundation Topics
Foundation Summary

Chapter Description

This chapter covers some of the most fundamental and important LAN topics with coverage of VLANs and VLAN trunking, including Etherchannel and PPP over Ethernet (PPPoE), in preparation for the CCIE Routing and Switching Exam.

From the Book

CCIE Routing and Switching Certification Guide, 4th Edition

$94.99

Blueprint topics covered in this chapter:

This chapter covers the following subtopics from the Cisco CCIE Routing and Switching written exam blueprint. Refer to the full blueprint in Table I-1 in the Introduction for more details on the topics covered in each chapter and their context within the blueprint.

VLANs
VLAN Trunking Protocol (VTP)
Etherchannel
PPP over Ethernet (PPPoE)

This chapter continues with the coverage of some of the most fundamental and important LAN topics with coverage of VLANs and VLAN trunking. As usual, for those of you current in your knowledge of the topics in this chapter, review the items next to the Key Topic icons spread throughout the chapter, plus the "Foundation Summary" and "Memory Builders" sections at the end of the chapter.

"Do I Know This Already?" Quiz

Table 2-1 outlines the major headings in this chapter and the corresponding "Do I Know This Already?" quiz questions.

Table 2-1. "Do I Know This Already?" Foundation Topics Section-to-Question Mapping

Foundation Topics Section	Questions Covered in This Section	Score
Virtual LANs	1–2
VLAN Trunking Protocol	3–5
VLAN Trunking: ISL and 802.1Q	6–9
Configuring PPPoE	10
Total Score

In order to best use this pre-chapter assessment, remember to score yourself strictly. You can find the answers in Appendix A, "Answers to the 'Do I Know This Already?' Quizzes."

Assume that VLAN 28 does not yet exist on Switch1. Which of the following commands, issued from any part of global configuration mode (reached with the configure terminal exec command) would cause the VLAN to be created?
1. vlan 28
2. vlan 28 name fred
3. switchport vlan 28
4. switchport access vlan 28
5. switchport access 28
Which of the following are the two primary motivations for using private VLANs?
1. Better LAN security
2. IP subnet conservation
3. Better consistency in VLAN configuration details
4. Reducing the impact of broadcasts on end-user devices
5. Reducing the unnecessary flow of frames to switches that do not have any ports in the VLAN to which the frame belongs
Which of the following VLANs can be pruned by VTP on an 802.1Q trunk?
1. 1–1023
2. 1–1001
3. 2–1001
4. 1–1005
5. 2–1005
An existing switched network has ten switches, with Switch1 and Switch2 being the only VTP servers in the network. The other switches are all VTP clients and have successfully learned about the VLANs from the VTP servers. The only configured VTP parameter on all switches is the VTP domain name (Larry). The VTP revision number is 201. What happens when a new, already-running VTP client switch, named Switch11, with domain name Larry and revision number 301, connects via a trunk to any of the other ten switches?
1. No VLAN information changes; Switch11 ignores the VTP updates sent from the two existing VTP servers until the revision number reaches 302.
2. The original ten switches replace their old VLAN configuration with the configuration in Switch11.
3. Switch11 replaces its own VLAN configuration with the configuration sent to it by one of the original VTP servers.
4. Switch11 merges its existing VLAN database with the database learned from the VTP servers, because Switch11 had a higher revision number.
An existing switched network has ten switches, with Switch1 and Switch2 being the only VTP servers in the network. The other switches are all VTP clients, and have successfully learned about the VLANs from the VTP server. The only configured VTP parameter is the VTP domain name (Larry). The VTP revision number is 201. What happens when an already-running VTP server switch, named Switch11, with domain name Larry and revision number 301, connects via a trunk to any of the other ten switches?
1. No VLAN information changes; all VTP updates between the original VTP domain and the new switch are ignored.
2. The original ten switches replace their old VLAN configuration with the configuration in Switch11.
3. Switch11 replaces its old VLAN configuration with the configuration sent to it by one of the original VTP servers.
4. Switch11 merges its existing VLAN database with the database learned from the VTP servers, because Switch11 had a higher revision number.
5. None of the other answers is correct.
Assume that two brand-new Cisco switches were removed from their cardboard boxes. PC1 was attached to one switch, PC2 was attached to the other, and the two switches were connected with a cross-over cable. The switch connection dynamically formed an 802.1Q trunk. When PC1 sends a frame to PC2, how many additional bytes of header are added to the frame before it passes over the trunk?
1. 0
2. 4
3. 8
4. 26
Assume that two brand-new Cisco Catalyst 3550 switches were connected with a cross-over cable. Before attaching the cable, one switch interface was configured with the switchport trunk encapsulation dot1q, switchport mode trunk, and switchport nonegotiate subcommands. Which of the following must be configured on the other switch before trunking will work between the switches?
1. switchport trunk encapsulation dot1q
2. switchport mode trunk
3. switchport nonegotiate
4. No configuration is required.
When configuring trunking on a Cisco router fa0/1 interface, under which configuration modes could the IP address associated with the native VLAN (VLAN 1 in this case) be configured?
1. Interface fa 0/1 configuration mode
2. Interface fa 0/1.1 configuration mode
3. Interface fa 0/1.2 configuration mode
4. None of the other answers is correct
Which of the following is false about 802.1Q?
1. Encapsulates the entire frame inside an 802.1Q header and trailer
2. Supports the use of a native VLAN
3. Allows VTP to operate only on extended-range VLANs
4. Is chosen over ISL by DTP
Which command enables PPPoE on the outside Ethernet interface on a Cisco router?
1. pppoe enable
2. pppoe-client enable
3. pppoe-client dialer-pool-number
4. pppoe-client dialer-number

2. Foundation Topics | Next Section

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.

Privacy Notice

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@ciscopress.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
Such marketing is consistent with applicable law and Pearson's legal obligations.
Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.ciscopress.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

As required by law.
With the consent of the individual (or their parent, if the individual is a minor)
In response to a subpoena, court order or legal process, to the extent permitted or required by law
To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
To investigate or address actual or suspected fraud or other illegal activities
To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020

Email Address