MPLS Questions

ETT-MODULE 1

QUESTION SET ON MPLS

1. What is MPLS and why it is being so popular in short time?2. Why MPLS is called multi protocol?3. What is the protocol used by MPLS?4. What are the advantages and applications of MPLS?5. What is the difference between VPN and MPLS?6. What is a label? What is the structure of the label?7. Where will the label be imposed in a packet?8. What is a Forwarding Equivalence Class (FEC)?9. What do the terms incoming, outgoing, local, and remote mean when referring to labels?10. Explain the architecture of an MPLS network?11. What is downstream and upstream router in MPLS? 12. Explain the format of the MPLS label?13. Describe the stack of MPLS label and explain where it resides in the frame?14. What s label switch router? What function does it perform?15. What are labeled switch path and forwarding equivalence class?16. In which layer does MPLS fits in an OSI reference model?17. Which table does an LSR use to forward packets?18. Explain how label packets are forwarded?19. Why does the MPLS labels have TTL field? Explain what happen to the packets that have

TTL expiring?20. Explain the need and operation of LDP?

Submitted by:

Tushar Saxena

M.Tech-TSE

A1637012004

MPLS QUESTIONS

1. What is the difference between VPN and MPLS?2. What is MPLS and why it is being so popular in short time?3. What is the protocol used by MPLS?4. MPLS works on which layer?5. What is the difference between P and PE router?6. Can I make my PE router as P?7. Two routers are having 4 equal cost links, how many ldp sessions will be established?8. My LDP router id, OSPF router id and BGP router id is different, will it work to forward

the traffic of customers or not?9. What is Penultimate Hop Popping and why it is required? Which router performs the

PHP function?10. What are the different types of labels?11. How to make customer route unique?12. What is the difference between RD and RT?13. Can I assign a same RD to two different customers?14. Is RD travels in route update?15. What is downstream on demand?16. How to filter MPLS labels?17. What is the default range of MPLS labels in Cisco routers? How to extend that range?18. What is the difference between VPNv4 and IPv4 address family?19. Default timers of LDP?20. What is transport address?

HIMANSHU AGARWAL A1637012013

M TECH(TSE)

QUESTIONS ON MPLS

1.What is MPLS and why it is being so popular in short time?

2.What problem does MPLS solve?

3.How MPLS works?

4.What is the protocol used by MPLS?

5.What is downstream on demand?

6.What is a label switch path?

7.What is a label distribution protocol?

8.What is the relationship between MPLS and the Interior Routing Protocol ?

9.What is a “forward equivalency class”?

10.How are label switch path built?

11.What other protocols does MPLS support besides IP?

12.What are the differences between MPLS and ATM?

13.How does MPLS Traffic engineering accomplish?

14.How does MPLS merge Traffic flows?

15.How are loops prevented in MPLS network?

16.How does MPLS perform failure recovery?

17.What differences are there in running MPLS in OSPF versus IS-IS environment?

18.How does MPLS enables VPNs?

19.What kind of QoS protocol does MPLS supports?

20.How are MPLS network managed?

Submitted by:-

kanak priya (A1637012007)

Questions on MPLS

Q1. What is Multi−Protocol Label Switching (MPLS)?

Q2.What are the advantages of MPLS over IP?

Q3.What is a label? What is the structure of the label?

Q4.How does MPLS works?

Q5.What do you understand by label switching?

Q6.Where will the label be imposed in a packet?

Q7.What is a Forwarding Equivalence Class (FEC)?

Q8.What is an upstream label switch router (LSR)? What is a downstream LSR?

Q9.What is the characteristics of MPLS?

Q10.What are the functional components that is used in MPLS?

Q11.What does the terms incoming, outgoing, local, mean when referring to labels?

Q12.Explain in brief LSR, LER and LSP?

Q13.What are the components presents in Label Switching Forward Table?

Q12.How does the LSR know which is the top label, bottom label, and a middle label of the label stack?

Q14.What is the range of label values? What label values are reserved? What do the reserved values signify?

Q15.Explain Label Switching Algorithm?

Q16.How label switching algorithm work in MPLS.

Q17. What are the different types of messages that are carried by LDP?

Q18.What are the steps that are required for the data to be travel through MPLS domain?

Q19.What is the concept of tunneling in MPLS.?

Q20.What is the protocol stack architecture of MPLS.What are its advantages & disadvantages?

Ankita Awasthi

Enrollment no:A1637012005(M.tech TSE)

EMERGING TELECOM TECHNOLOGY

1. What is MPLS?

2. What problms does MPLS solve ?

3. What is label ?

4. What is lable switch path ?

5. What is lable distribution frame ?

6. What’s the difference between CR-LDP and RSVP-TE ?

7. What is forwarding equivalance class ?

8. What is LER and LSR in MPLS ?

9. What are differences between MPLS and ATM ?

10. What does traffic engineering accomplish ?

11. What are the components of MPLS-TE ?

12. Explain the operation of MPLS ?

13. How does MPLS enable VPNs ?

14. What kind of Qos protocol does MPLS support ?

15. What are the advantages and disadvantages of MPLS ?

16. Explain flow control in MPLS?

17. How does tunneling done in MPLS ?

18. What are the limitations of MPLS ?

19. What is GMPLS ?

20. What are the components of GMPLS ?

Submited by:

NEHA KUMARI

(A1637012008)

MPLS IMPORTANT QUESTIONS

1. What are the various MPLS applications?

2. Name three advantages of running MPLS in a service provider network.

3. What are the advantages of the MPLS VPN solution for the service provider over all the

other VPN solutions?

4. Name two pre-MPLS protocols that use label switching.

5. What do the ATM switches need to run so that they can operate MPLS?

6. Name the four fields that are part of a label.

7. How many labels can reside in a label stack?

8. In which layer does MPLS fit in the OSI reference model?

9. Which table does an LSR use to forward labeled packets?

10. Why does the MPLS label have a Time To Live (TTL) field?

11. What does the push operation do on a labeled packet?

12. Why does an LSR forward the ICMP message “time exceeded” along the LSP of the

original packet with the TTL expiring instead of returning it directly?

13. Name the advantages of MPLS traffic engineering.

14. What are the components of MPLS traffic engineering?

15. What are the attributes of the links enabled for traffic engineering?

16. Name the six ways how you can forward IP traffic onto a TE tunnel.

17. When you have an MPLS VPN network and TE tunnels that do not always have the PE

routers as head/tail end routers, what do you need to have?

18. Why do you need a link-state routing protocol for MPLS TE?

19. Why do MPLS VPN packets have two MPLS labels?

20. When would you use different route distinguishers for routes of the same VPN?

-U. PAVAN KUMAR

( A1637012011 )

Q1. What is Multi-Protocol Label Switching (MPLS)?

Q2. What is a label? What is the structure of the label?

Q3. Where will the label be imposed in a packet?

Q. What is a Forwarding Equivalence Class (FEC)?

Q4. Can an LSR transmit/receive non-MPLS on an MPLS interface?

Q5. Can an LSR receive/transmit a labeled packet on a non-MPLS interface?

Q6. How does the LSR know which is the top label, bottom label, and a middle label of the label stack?

Q7. What is the difference between VPN and MPLS?

Q8. Why MPLS is called multi protocol?

Q9. How does LDP Initializes?

Q10. What is FEC in traditional IP routing and MPLS?

Q11. Difference between MPLS and GMPLS

Q12. Advantages of MPLS.

Q13. Compare MPLS and Frame relay

Q14. Compare MPLS and ATM

Q15.  Where does the MPLS label live in a data frame?

Q16. Why does the MPLS label have a Time To Live (TTL) field?

Q17. Explain the need and operation of LDP.

Q18. How can you reduce the number of label bindings on an LSR?

Q19. Determine how labels are distributed in an MPLS network

Q20. What are the applications of MPLS

By :

Richa Budhiraja

Q1. Name the four fields that are part of a label.

Q2. Explain how labeled packets are forwarded

Q3. Explain what happens to labeled packets that have TTL expiring

Q4. Explain the driving factors behind MPLS

Q5. List the benefits of forwarding labeled packets instead of forwarding IP packets

Q6. Explain the applications of MPLS that have received widespread acceptance

Q7. Describe a stack of MPLS labels and explain where it resides in the frame

Q8. What a label switch router is and what functions it needs to perform

Q9. Determine how labels are distributed in an MPLS network

Q10. What is the fundamental purpose of LDP?

Q11. How can you reduce the number of label bindings on an LSR?

Q12. Difference between MPLS & GMPLS

Q13. Difference between MPLS & FRAME RELAY

Q14. Difference between MPLS & ATM

Q15. How does the LSR know which is the top label, bottom label, and a middle label of the label stack?

Q16. Can an LSR transmit/receive a non-MPLS on an MPLS interface?

Q17. What benefit do we achieve by using MPLS tunnels?

Q18. What benefit do we achieve by using MPLS tunnels?

Q19. Which table does an LSR use to forward labeled packets?

Q20. Why MPLS is called multi protocol?

By

Neeraj Kumar

QUESTIONS ON MPLS

By: PRASHANT SINGH

A1637012001

What is Multi-Protocol Label Switching (MPLS)?

What is a label? What is the structure of the label?

Where will the label be imposed in a packet?

What is a Forwarding Equivalence Class (FEC)?

What is an upstream label switch router (LSR)? What is a downstream LSR?

Is R3 a "Downstream" LSR to R4 for 10.1.1.0/24?

What do the terms incoming, outgoing, local, and remote mean when referring to labels?

Can an LSR transmit/receive a native IP packet (non-MPLS) on an MPLS interface?

Can an LSR receive/transmit a labeled packet on a non-MPLS interface?

What platforms and Cisco IOSes support MPLS?

Generic Routing Encapsulation (GRE) tunnel has an overhead of 24 bytes. How much

overhead does an MPLS LSP tunnel have?

How does the LSR know which is the top label, bottom label, and a middle label of the

label stack?

What is the range of label values? What label values are reserved? What do the reserved

values signify?

What protocol and port numbers do LDP and TDP use to distribute labels to LDP/TDP

peers?

What restrictions exist for MPLS support on the Catalyst 6500 and 7600 Optical Services

Router (OSR)?

Where can I find MPLS configuration samples?

What options are available for load balancing MPLS packets?

Can we configure an 802.1Q trunk between two Cisco Catalyst switches on different sites

over a MPLS connection?

Does the outgoing MPLS EXP value inherit the DSCP value in incoming IP packets by

default or is the incoming DSCP trusted without any additional configuration on an

MPLS enabled interface?

Does DHCP relay function work in the MPLS VPN network?

EMERGING TELECOM TECHNOLOGIES

Course Code: MCE 303

Credit Units: 04

1Q) Does the service provider track & monitor the entire network.

2Q) Can it secure its own network traffic & manage priority traffic across other networks?

3Q) What are the performance thresholds for network latency & availability?

4Q) How is performance measured & delivered to you?

5Q) Are there procedures for on-the-fly load rebalancing, security assessment and regular

backup.

6Q) Can its data centre supports your requirements for physical & network security capacity,

availability, operations and backbone connectivity.

7Q) How quickly will the provider respond to business change?

8Q) What are the terms if the network goes down or the level of service is not maintained?

9Q) What type of connectivity is supported on the network? Can incorporate Voice, data,

mobile, video, mobile to mobile into the MPLS network ?

10Q) What is the difference between MPLS & VPN.

11Q) What is the difference between MPLS & GMPLS.

12Q) What is the requirement of GMPLS.

13Q) Explain the operation of MPLS.

14Q) What is the advantage of GMPLS over MPLS.

15Q) Explain label format in MPLS.

16Q) Explain the mechanism label switching, label allocation, label stacking, label switching in

MPLS.

17Q) Explain TTL( time to live) in MPLS label format.

18Q) What are the five phases of LDP session.Explain it briefly.

19Q) What is lambda switching? ( GMPLS)

20Q) Explain flow control mechanism in MPLS?

BY

Neha Kumari(2009)

1. What components/services are provided with the MPLS circuit order?

2. Which statement correctly describes the disabling of IP TTL propagation in an MPLS

network?

3. A network is composed of several VRFs. It is required that VRF users VRF_A and VRF_B

be able to route to and from VRF_C, which hosts shared services. However, traffic must not

be allowed to flow between VRF_A and VRF_B. How can this be accomplished?

4. What is the difference between VPN and MPLS?

5.  What is the difference between P and PE router?

6. What is Penultimate Hop Popping and why it is required? Which router performs the PHP

function?

7. How to filter MPLS labels?

8. What is the default range of MPLS labels in Cisco routers? How to extend that range?

9. What is MP-iBGP? Can we use normal BGP in lieu of MP-iBGP?

10. What is CEF and without enabling CEF, can we make MPLS work?

11. In neighbor discovery command, I am receiving only xmit, what does it mean?

12. What is the difference between VPNv4 and IPv4 address family?

13. What problems does MPLS solve?

14. What are the different types of MPLS VPNs?

15. Does the outgoing MPLS EXP value inherit the DSCP value in incoming IP packets by

default or is the incoming DSCP trusted without any additional configuration on an MPLS

enabled interface?

16. Does DHCP relay function work in the MPLS VPN network?

17. How does the LSR know which is the top label, bottom label, and a middle label of the label

stack?

18. What restrictions exist for MPLS support on the Catalyst 6500 and 7600 Optical Services

Router (OSR)?

19. What do the terms incoming, outgoing, local, and remote mean when referring to labels?

20. Generic Routing Encapsulation (GRE) tunnel has an overhead of 24 bytes. How much

overhead does an MPLS LSP tunnel have?

BY amritpal

1. Differentiate Between MPLS And MPLS-Tp.

2. What Are The Advantages Of MPLS For Mobile Backhaul?

3. Differentiate Ethernet Vs. MPLS-TP For Connection-Oriented Ethernet.

4. Explain Benefits Of MPLS Networks?

5. What Are The Different Types Of MPLS VPNS Deployed In Todays Network?

6. On which layer MPLS is operated?

7. What is stack?

8. What are the fields of stack in MPLS?

9. What are LSRs, LERs, LPDs and LSP?

10. What are push, pop and swap operations?

11. What are two standardized protocols for managing MPLS paths?

12. Compares the MPLS with following

a) ATM

b) Frame Relay

13. What are the advantage and disadvantage of MPLS?

14. Show the layered model of MPLS.

15. Explain MPLS Packet Encapsulation & MPLS Header Fields.

16. Explain different types of LSPs in MPLS.

17. Explain pseudowire using LDP.

18. Who are the competitors of MPLS?

19. What problems does MPLS solved ?

20. What is the status of the MPLS standard?

By : prabhat kumar

By Rahul Raj

1. What is MPLS? What are its characteristics?2. Explain network layer routing in MPLS.3. How MPLS works?4. What is LDP and why is it used?5. What is a label and what is its importance?6. How the label switching tables are formed?7. What are LSPs, LER and LSR.8. Explain tunneling.9. List the advantages and disadvantages of MPLS.10. Explain the label switching algorithm.11. What is binding?12. Explain the different types of binding?13. Draw and explain MPLS protocol stack architecture?14. What is SHIM? Draw and explain the format of SHIM?15. Explain the methods by which the label binding information can be distributed.16. What is the role of traffic engineering in MPLS?17. What is GMPLS and why was it required?18. Explain flow control in MPLS and GMPLS.19. What are PDUs?20. Explain MPLS operation.

Anshika Salaria

(A1637012014)

20 Questions by NAVIN PAUDEL (A1637012010), M.tech -TSE

Q1. Explain basic core MPLS technology and concepts

Q2. What is a label? What is the structure of the label? Where will the label be imposed in a packet?

Q3. What is an upstream label switch router (LSR)? What is a downstream LSR?

Q4. What do the terms incoming, outgoing, local, and remote mean when referring to labels?

Q5 (a). Can an LSR transmit/receive a native IP packet (non-MPLS) on an MPLS interface?

5(b). Can an LSR receive/transmit a labeled packet on a non-MPLS interface?

Q6. How does the LSR know which is the top label, bottom label, and a middle label of the label stack?

Q7. What is the range of label values? What label values are reserved? What do the reserved values signify?

Q8. Describe the characteristics and behaviors of Label Distribution in Frame-mode MPLS

Q9. Explain Convergence in Frame-mode MPLS

Q10. Describe the characteristics and behaviors of Label Distribution over LC-ATM Interfaces and VC Merge

Q11. Describe the features of MPLS Label Allocation, Distribution, and Retention Modes

Q12. Explain the process of LDP Neighbor Discovery

Q13. Describe the characteristics and functions of Virtual Private Networks

Q14. Describe Overlay and Peer-to-Peer VPNs

Q15. Explain Major VPN Categorization

Q16. Describe MPLS VPN Architecture

Q17. Describe the MPLS VPN Routing Model

Q18. Explain the process of MPLSVPN Packet Forwarding

Q19. Explain Switching and Forwarding Operation on MPLS

Q20. How Flow control is done in MPLS?

o What is MPLS?

o What are its applications?

o Explain 3 advantages of MPLS N/W?

o Name two pre-MPLS protocols to use label switching?

o What does the ATM switches need to run so that they can operate MPLS?

o How to insure Optimal Traffic flow between all the customer sites in an ATM or Frame

Relay overlay N/W?o Name all fields of label?

o How many labels can reside in a label stack?

o In which layer MPLS fit in the OSI reference Model?

o Which table does an LSR use to forward label packet?

o Why does MPLS label have a TTL field?

o What does push operation do in label packet?

o What are the value and the functions of Router Alert Label?

o Why are MTU and MRU such an important Parameters in MPLS networks?

o Is using Path MTU Discovery a guarantee that there will be no MTU problems in the MPLS

network?o What is the fundamental Purpose of LDP?

o What are label switched pathLSP and a forwarding equivalence classFEC?

o Determine how labels are distributed in MPLS?

o Name 4 main functions that LDP takes care of?

o How can you reduce the number of label bindings on an LSR?

By himanshu goyal

1. What is the difference between VPN and MPLS?2. What is MPLS and why it is being so popular in short time?3. What is the protocol used by MPLS?4. MPLS works on which layer?5. What are the different types of labels?6. What is downstream on demand?7. How to filter MPLS labels?8. What is the RFC of MPLS?9. Why MPLS is called multi-protocol?10. What is the difference between MPLS, SSL and IPSec?11. Does MPLS support IPv6?12. Can I use the existing IPv4 MPLS backbone for IPv6?13. What is forward equivalence class aka FEC?14. What is adjacency table?15. Difference between MPLS IP and MPLS Label Protocol LDP command?16. What is downstream and upstream router in MPLS?17. How Does LDP Initializes?18. what is FEC in traditional IP routing and MPLS?19. What is the difference between Optimum, Fast and CEF Switching?20. Advantages of MPLS.

BY Nandini Deb