CCNA Exam Certification Guide is a best-of-breed Cisco 642-321 exam study guide that has been completely updated to focus specifically on the objectives.Senior instructor and best-selling author Wendell Odom shares preparation hints and HP0-Y36 tips to help you identify areas of weakness and improve both your conceptual and hands-on knowledge.Cisco 642-321 Material is presented in a concise manner, focusing on increasing your understanding and retention of exam topics.

Exam A
QUESTION 1
Which timing mode is most appropriate for an ONS 15454 that has lost its BITS-1 and optical references?
A. line timing
B. loop timing
C. internal timing
D. through timing
E. external timing

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 2
With R4.0, how many total DCC-R tunnel connections can each ONS 15454 support using the TCC+ card?
A. 10
B. 32
C. 64
D. 84
E. 96

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 3
What is the difference between 1+1 and 1:1 protection switching?
A. 1+1 is based on APS, while 1:1 is based on IPS.
B. 1:1 is used in SNCP switching, while 1+1 is used in MS-SPRing switching.
C. 1+1 sends signals on Working and Protect paths, while 1:1 sends signals only on Working path.
D. 1+1 sends signals on Working path ONLY, while 1:1 sends signals on both Working and Protect paths.

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 4
You are provisioning an E-1 circuit on an ONS 15454 MS-SPRing configuration and XC-VXL-10G card. Each VC-12 connection must also terminate via the VC-3 matrix. How many VC-3 ports remain after this circuit is created, assuming no other circuits?
A. 92
B. 93
C. 94
D. 95
E. 96

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 5
Click the Task button. Place the steps for removing a node from an existing MS-SPRing ring in the proper order.

A.
B.
C.
D.

Correct Answer: Section: (none) Explanation
Explanation/Reference:
Answer: Check certifyme eEngine, Download from Member Center
QUESTION 6
Click the Exhibit button. In the DCN connection shown in the exhibit, all non-GNE nodes are located on different subnets from the GNE. There are no static routes or external OSPF on any elements. ??CTC workstation and GNE have Router as its default gateway. Can the CTC workstation see the entire SDH network?

A. Yes, but only if the CTC’s network address is a static route in the GNE.
B. Yes, because the GNE will only serve as a proxy-ARP for elements on the same subnet.
C. Yes, but only if the router’s address is entered as a static route in the non-GNE elements.
D. Yes, because the GNE will serve as a proxy-ARP for all elements, regardless of their subnets.

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 7
What protocol enables Ethernet over SONET/SDH encapsulation interoperability between the G-series and ML-series Ethernet cards?
A. LEX
B. HDLC
C. GFP-F
D. PPP/BCP

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 8
What is the correct relative switching priority in an MS-SPRing ring (higher to lower)?
A. signal fail, signal degrade, manual switch
B. signal degrade, signal fail, manual switch
C. protection lockout, manual switch, path AIS
D. forced switch, manual switch, signal degrade E. protection lockout, manual switch, forced switch

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 9
Click the Task button. Place the steps for adding a new node to an existing MS-SPRing ring in the proper order.

A.
B.
C.
D.

Correct Answer: Section: (none) Explanation
Explanation/Reference:
Answer: Check certifyme eEngine, Download from Member Center
QUESTION 10
A customer has 2 E1s to add between far-end nodes in an SNCP ring. What type of circuit should you recommend?
A. LO-PATH circuits
B. HO-PATH circuits
C. 1:1 protection circuits
D. 1:N protection circuits
E. LO-TUNNEL tunnel circuits

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 11
Click the Exhibit button. As shown in the exhibit, a customer has several interconnected core rings. They want to create several irtual rings?utilizing their STM-64 backbone (nodes 1, 2, 3, and 4). What do you recommend?

A. SNCP rings
B. MS-SPRing rings
C. 1:N protection on all core circuits
D. dual-ring interconnect with MS-SPRing rings

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 12
A customer has 20 E1s to add between far-end nodes in an SNCP ring. What type of circuit would you recommend?
A. LO-PATH circuits
B. HO-PATH circuits
C. 1:1 protection circuits
D. 1:N protection circuits
E. LO-PATH tunnel circuits

Correct Answer: E Section: (none) Explanation
Explanation/Reference:
QUESTION 13
A customer would like to create a 1:1 protection group with a DS3Ni-12 card. Where should it be placed in the chassis?
A. only Slots 6 or 12
B. only Slots 3 or 15
C. high or low speed slots
D. directly adjacent to the working card
E. high-speed slots only (5/6 and 12/13)

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
The VVJHV contains more than 400 practice questions for the Cisco 642-321 exams, including simulation-based questions. Also contains hands-on exercises and a customized copy of the Cisco 642-321 exams network simulation software.