Implementing Cisco MPLS q &a 4m Cisco Set 1

8/2/2019 Implementing Cisco MPLS q &a 4m Cisco Set 1

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Implementing Cisco MPLS (MPLS) Review

Questions - Set 1

Legend

answer Correct answer

Your answer, Correct.

Your answer, Incorrect.

1. What are three foundations of traditional IP routing? (Choose three.) Routing protocols are used on all devices to distribute routing information. Regardless of protocol, routers always forward packets based on the IP destination address only(except for using PBR). Routing lookups are performed on every router.

Routing is performed by assigning a label to an IP destination.2. Which three statements are true? (Choose three.)

MPLS uses labels to forward packets.MPLS works only in IP networks.

MPLS labels can correspond to a Layer 3 destination address, QoS, source address, or Layer 2circuit. MPLS does not require a routing table lookup on core routers.

3. In MPLS TE, which two statements are true? (Choose two.)

Traditional IP routing does not support traffic engineering. Traditional IP routing would force all traffic to use the same path based on destination.

Using MPLS TE, traffic can be forwarded based on parameters such as QoS and source address.

MPLS does not support traffic engineering.4. Which three statements are true? (Choose three.)

In frame-mode MPLS, labels are typically inserted between the Layer 2 header and the Layer 3header.

MPLS labels are inserted after the Layer 3 header in frame-mode MPLS. In cell-mode MPLS, MPLS uses the VPI/VCI fields as the label.

MPLS labels are 32 bits.5. Which two statements are true? (Choose two.)

Usually one label is assigned to an IP packet.Usually two labels are assigned to an IP packet.

Two labels will be assigned to an MPLS VPN packet.

One label will be assigned to an MPLS VPN packet.6. What are two normal functions of an edge LSR? (Choose two.)

impose labels at the ingress routerimpose labels at the egress routerpop labels at the ingress router

pop labels at the egress router7. Which two statements are true regarding RSVP? (Choose two.) RSVP is used to create an LSP tunnel.


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RSVP propagates labels for TE tunnels.RSVP assigns labels for TE tunnels.

RSVP is not used to create an LSP tunnel.8. Which two statements are true regarding interactions between MPLS applications? (Choose

two.)

The forwarding plane is the same for all applications.Differences exist in the forwarding plane depending on the MPLS application.The control plane is the same for all applications.

Differences exist in the control plane depending on the MPLS application.9. LDP and TDP use which two well-known port numbers? (Choose two.)

LDP uses 464. LDP uses 646.

TDP uses 646. TDP uses 711.

10. Which three of the answer choices are contained in the LFIB? (Choose three.)

local generated label

outgoing labelLocal Address next-hop address11. Which two tables contain label information? (Choose two.)

LIBmain IP routing tableFLIB

LFIB12. Which two statements are correct? (Choose two.)

LSPs are bidirectional. LSPs are unidirectional.

LDP advertises lables for LSP LDP advertises labels only for individual segments in the LSP.

13. Upon a link failure, which three tables are updated to reflect the failed link? (Choose three.)

LIB

LFIB

FIBFLIB

14. Upon a link recovery, which three tables are updated to reflect the failed link? (Choose three.)

LFIBFLIB

FIB

LIB15. Which two steps are NOT mandatory to enable MPLS? (Choose two.)

Enable CEF switching. Configure the size of the label pool.

Configure the MTU size for labeled packets.Configure LDP (or TDP) on every interface that will run MPLS.

16. Which two of the answer choices would cause an LDP (or TDP) session NOT to be established

between two LSRs? (Choose two.)


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an access list that allows TCP/UDP port number 646an access list that allows TCP/UDP port number 711

an access list that does not allow TCP/UDP port number 646

an access list that does not allow TCP/UDP port number 71117. When you are using a dynamic routing protocol such as RIP in a redundant hub-and-spoke

topology, which statement is true?Static routing must be used to provide connectivity from remote site to remote site.Split-horizon updates must be disabled at the hub router if static routing is used.

Split-horizon updates must be disabled at the hub router if point-to-point subinterfaces are not

used.Split-horizon updates must be enabled at the remote site router when point-to-point subinterfaces

are not used.18. In which two ways do MPLS VPNs support overlapping customer address spaces? (Choose

two.) by implementing unique RDs for each customer

by implementing unique RTs for each customerby implementing different LSPs for each customer

by implementing virtual routing spaces for each customer19. Which two types of routes would an MPLS VPN install into the VRF? (Choose two.)

those routes received via an IPv4 update those routes received via a VPNv4 update

those routes received via the core IGP update those routes received via the customer IGP update

20. What is the impact of changing a BGP next hop on an MP-BGP update at confederation

boundaries?The packet will be forwarded but over a suboptimal route.

Packet forwarding for the affected destination will be interrupted.

The first P router of the confederation that receives the packet will have to perform a routing table

lookup to identify the MP-IBGP next hop.

The ingress PE router will forward an MPLS packet to the router identified as the next hop, whereit will be converted to an IP packet and forwarded via MP-IBGP.

21. Which two protocols are VPN-aware? (Choose two.)

RIPv2

IS-ISODR

EIGRP22. A PE router is supporting site A for a VPN on one interface using RIP as the routing protocol.

Site B belongs to the same VPN and is being supported on a second interface using EBGP asthe routing protocol. Why is it necessary to redistribute the RIP-learned route into the per-VRFinstance of the BGP process?

to allow site A and B to communicate with each otherto allow the RIP route to be propagated to the VRF routing tablesto allow the RIP routes to be propagated to the local EBGP session

to allow the RIP routes to be propagated through the backbone MP-BGP process to other PE

routers23. Which two VRF parameters specify the extended community attribute used in VPNv4 BGP?

(Choose two.)rd route-distinguisher


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route-target export RT

route-target import RTip vrf forwarding vrf-name

24. You have created a configuration that defines three import route targets (65001:01, 65002:02,

and 65003:03) for a VRF. A route update has three RTs (65003:03, 65004:04, and 65005:05)

attached to it. How will this update be processed and why?The update will be accepted by the VRF because it matches the import RD of 03.

The update will be discarded by the VRF because it does not match all of the RTs in the import

list. The update will be accepted by the VRF because it matches at least one of the RTs in the importlist.

The update will be discarded by the VRF because it does not match all of the RDs in the import

list.25. What are the two major design models for implementing Internet access and MPLS VPNs?

(Choose two.) using a separate VPN for Internet access

using global route leaking using globa using global routing on PE routers oute leakin

using default routesusing global routing on PE routersusing default routes

Number answered correctly: 17 out of 25.

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Implementing Cisco MPLS q &a 4m Cisco Set 1