Question 1

Which of the following statements about inter-AS model B VPRN is FALSE?

Accepted Answer

A)   Model B does not require the configuration of VPRN instances on the ASBRs.
B)   The ASBRs exchange data packets that are encapsulated with a transport label and a service label.
C)   The route target advertised in one AS is maintained and used in the remote AS.
D)   The CLI command "configure router bgp enable-inter-as-vpn" is required on the ASBRs. B

Question 2

Which of the following statements best describes the output?

Accepted Answer

A)   The AS-Path is not present because a policy is configured on PE2 to set it to null.
B)   The AS-Path is not present because a policy is configured on CE1 to set it to null.
C)   The AS-Path is not present because a policy is configured on PE1 to set it to null.
D)   The AS-Path is not present because VPN-IPv4 routes do not propagate the IPv4 AS-Path BGP attribute. C

Question 3

Based on the VPRN BGP decision process, which of the following routes is selected first if the command "PE1>config>service>vprn> bgp best-path-selection as-path-ignore" is executed?

Accepted Answer

A)   The route learned from an eBGP peer.
B)   The route with the lowest Origin.
C)   The route with the lowest originator ID or BGP Identifier.
D)   The route with the shortest AS path. B

Question 4

Where can network-queue policies be applied on a Nokia 7750 SR?

Accepted Answer

A)   On access port egress.
B)   On network port ingress.
C)   On MDA ingress.
D)   On IOM egress.

Question 5

Which of the following statements about the Route Target is TRUE?

Accepted Answer

A)   The Route Target is added to an IPv4 route to create the VPN-IPv4 route.
B)   The Route Target is an extended community string that identifies VPN membership.
C)   A route can only have one Route Target.
D)   The Route Target is a 64-bit value added to customer prefixes to make them unique.

Question 6

How is MAC learning achieved in traditional Ethernet switches?

Accepted Answer

A)   As frames leave the switch, the DA is populated into the FDB.
B)   As frames enter the switch, the DA is populated into the FDB.
C)   As frames leave the switch, the SA is populated into the FDB.
D)   As frames enter the switch, the SA is populated into the FDB.

Question 7

A VPLS is configured with service MTU of 2000 and a Q-in-Q SAP. What is the minimum MTU required for the SAP to become operational?

Accepted Answer

A)   2008
B)   2004
C)   2000
D)   1992

Question 8

Which of the following statements about the Inter-AS model A VPRN is TRUE?

Accepted Answer

A)   It is the most scalable of the Inter-AS models.
B)   VRF configuration is not required on the ASBRs.
C)   Most routers that support VPRN functionality do not support model A by default.
D)   It is not necessary to run MPLS at the boundary between autonomous systems.

Question 9

AS 65100 is advertising 192.168.1.0/27 into BGP. Which of the following AS Paths would the prefix 192.168.1.0/27 contain when viewed on router R8?

Accepted Answer

A)   65200 (65206 65202)  65100
B)   (65206 65202)  65100
C)   65250 (65206 65202)  65100
D)   65200 65100

Question 10

For the Inter-AS model C VPRN, which of the following is FALSE when an IP packet is sent from 192.1.1.1 to 192.2.1.1?

Accepted Answer

A)   PE1 pushes three labels on the IP packet: a VPN label, a BGP label, and an LDP transport label.
B)   ASBR1 pops the LDP label, swaps the BGP label and forwards the IP packet to ASBR2.
C)   ASBR2 swaps the BGP label and pushes an LDP transport label.
D)   PE2 pops all labels and forwards the unlabeled packet to its destination.

Question 11

Which of the following statements about the VPLS FDB is TRUE?

Accepted Answer

A)   An alarm will be raised when the FDB occupancy reaches 5 MAC entries.
B)   An alarm will be cleared when the FDB occupancy drops below 6 MAC entries.
C)   An alarm will be raised when the FDB occupancy reaches 7 MAC entries.
D)   An alarm will be cleared when the FDB occupancy drops below 10 MAC entries.

Question 12

Which regular expression will match the AS Path of a route originating in remote AS 65100?

Accepted Answer

A)   ".+ 65100"
B)   "65100.+"
C)   ".* 65100.*"
D)   "65100"

Question 13

Host 1 sends its first Ethernet frame into the VPLS. Which of the following statements about MAC learning is TRUE?

Accepted Answer

A)   Host 1 MAC will be learned on the SAP until it ages out.
B)   Host 1 MAC will be learned on the SAP until it is re-learned on the SDP.
C)   Host 1 MAC will be learned on the SAP and cannot age out or be re-learned locally.
D)   Host 1 MAC will be learned on the SAP until it ages out or is re-learned on the SDP.

Question 14

Which of the following is used by the far end PE node to identify a specific VPLS?

Accepted Answer

A)   SDP ID
B)   Service ID
C)   VC Label
D)   Transport Label
E)   Customer ID

Question 15

How was standard BGP modified to allow it to carry routing information for VPRNs?

Accepted Answer

A)   By using the MED attribute to carry the OSPF metric
B)   By adding an additional field to the BGP Update to carry the transport label
C)   By using the Cluster List attribute to carry the network prefix
D)   By defining support for the VPN-IPv4 address family

Question 16

You are configuring a VPLS spoke termination to a VPRN on a Nokia 7750 SR. The spoke SDP is running over a NULL encapsulated network port. The best practice is to set the VPRN interface "ip-mtu" equal to what value?

Accepted Answer

A)   The SDP path MTU minus 14
B)   The LMTU found in 'show router ldp bindings' on the VPLS side of the spoke SDP
C)   The configured service-mtu of the VPLS service
D)   The LMTU found in 'show router ldp bindings' on the VPLS side of the spoke SDP minus 14
E)   The SPD path MTU

Question 17

Which of the following statements about Carrier Supporting Carrier (CSC) VPRN is FALSE?

Accepted Answer

A)   CSC does not allow a customer carrier to offer Layer 2 services to its end customers.
B)   A CSC VPRN is configured on the network provider's CSC-PE routers.
C)   CSC eliminates the need for customer carriers to build and maintain their own MPLS backbone.
D)   The network provider provides an MPLS VPN backbone to the customer carrier.

Question 18

For the Carrier Supporting Carrier (CSC) VPRN, which routes are advertised between CSC-CE1 and CSC-PE1?

Accepted Answer

A)   VPN-IPv4 routes for all PE system addresses in AS 1000.
B)   BGP labeled IPv4 routes for all PE system addresses in AS 1000.
C)   VPN-IPv4 routes for all PE system addresses in AS 5000.
D)   BGP labeled IPv4 routes for all PE system addresses in AS 5000.

Question 19

What operation does a P device perform when it receives a labeled packet for a VPRN service?

Accepted Answer

A)   It forwards the packet based on the label signaled by MP-BGP.
B)   It decrements the TTL and forwards the packet based on the inner label.
C)   It swaps the outer label then forwards the packet.
D)   The P router does not perform any operations on labeled packets.

Question 20

Which of the following statements about assigning one Route Distinguisher per VPN is TRUE?

Accepted Answer

A)   This approach is recommended when multiple sites advertise the same prefix.
B)   This approach limits the opportunities for load balancing.
C)   This approach requires additional memory on the PEs to store more routes.
D)   This approach is recommended for extranet VPN.

Exam 3: Nokia Multiprotocol Label Switching