Deck 3: Nokia Multiprotocol Label Switching

Question 1

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

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.

Answer 1

The ASBRs exchange data packets that are encapsulated with a transport label and a service label.

Question 2

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?

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

Answer 2

The LMTU found in 'show router ldp bindings' on the VPLS side of the spoke SDP

Question 3

Which of the following is a benefit of a hub and spoke VPRN topology?

A) Reduced number of VPN tunnels that need to be managed.
B) Optimal routing between all sites.
C) Limited configuration required on the hub PE device.
D) Site to site redundancy support.

Answer 3

Reduced number of VPN tunnels that need to be managed.

Question 4

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

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 5

Which of the following statements best describes the output?

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.

Question 6

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

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 7

For the Inter-AS model B VPRN, which of the following is FALSE when CE2 sends an IP packet to 192.168.1.1?

A) PE2 pushes one label on the IP packet and forwards it to ASBR2.
B) ASBR2 forwards the IP packet with one label to ASBR1.
C) ASBR1 forwards the IP packet with two labels to PE1.
D) PE1 forwards an unlabeled IP packet to CE1.

Question 8

Community lists are configured for the PE hub and spoke VPRN. Which communities should be imported by the VPRN service on PE1?

A) "Spoke_Sites"
B) "Hub_Site"
C) "Spoke_Sites" and "Hub_Site"
D) No communities should be imported.

Question 9

A Nokia 7750 SR is configured with a policy to export directly connected networks to BGP. Which of the following commands verifies that the export was successful?

A) show router route-table
B) show router bgp routes
C) show router bgp routes hunt
D) show router bgp neighbor received-routes

Question 10

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

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 11

Which of the following statements regarding BGP FRR is FALSE?

A) The router must receive several BGP routes to compute a backup path.
B) BGP FRR can be triggered by BFD.
C) The backup path can use the same next-hop as the primary path.
D) BGP peer-tracking can be used to improve BGP FRR failure detection times.

Question 12

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?

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.

Question 13

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?

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

Question 14

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

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 15

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

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

Question 16

Which of the following statements about the configuration of an inter-AS model C VPRN is FALSE?

A) MP-iBGP sessions must be configured between the PE routers in each AS.
B) LDP must be configured in each AS.
C) MP-eBGP sessions must be configured between the ASBRs.
D) The ASBRs must be configured with "enable-inter-as-vpn".

Question 17

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

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 18

A Carrier Supporting Carrier (CSC) VPRN is configured on a Nokia 7750 SR for a customer carrier offering VPRN services. Which of the following about this configuration is FALSE?

A) In the CSC VPRN, configure an eBGP session between CSC-PE and CSC-CE and use the CLI command "advertise-label vpn-ipv4" to enable the advertisement of VPN-IPv4 routes.
B) When the customer carrier uses the same autonomous system number in various sites, use the CLI command "loop-detect off" to disable the loop detection functionality on CSC-CE and PE routers.
C) On the CS?-PE routers, use the CLI command "carrier-carrier-vpn" to configure the VPRN service as CSC.
D) Configure an iBGP session between PE1 and PE2 and use the CLI command "family vpn-ipv4" to directly exchange end-customer routes learned from CE1 and CE2.

Question 19

A Carrier Supporting Carrier (CSC) VRPN is configured on a Nokia 7750 SR for a customer carrier who is an Internet Service Provider (ISP). Which of the following configuration steps is NOT required?

A) Configuring labeled eBGP sessions between CSC-CE and CSC-PE routers.
B) Configuring a policy on each CSC-CE to advertise local PE addresses to the network provider.
C) Configuring labeled iBGP sessions between PEs residing in different customer carrier sites.
D) Advertising the received system addresses of remote PEs using either iBGP or IGP/LDP within each customer carrier site.

Question 20

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?

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 21

Which of the following is a characteristic of using a spoke SDP in an H-VPLS design?

A) Simplifies signaling.
B) Increases requirement for replication.
C) Increases MDU configuration complexity.
D) Increases the complexity of an inter-domain connectivity solution.

Question 22

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

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 23

For periodic traffic between hosts, which of the following statements about the use of remote and local age timers is TRUE on the Nokia 7750 SR?

A) The lower the age-time, the higher the probability of flooding of unknown traffic.
B) The higher the age-time, the higher the probability of flooding of unknown traffic.
C) The local and remote age timers are, by default, the same value.
D) There is no relationship between the age-timers and the probability of flooding of unknown traffic.

Question 24

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

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

Question 25

RSTP is running in the network. Which port will become the alternate port?

A) Bridge B 1/1/3
B) Bridge B 1/1/2
C) Bridge D 1/1/1
D) Bridge D 1/1/3
E) Bridge E 1/1/1
F) Bridge E 1/1/3

Question 26

According to the SAP-egress policy configured and applied, which queue will AF traffic use?

A) Queue 3, because it is explicitly defined in the SAP-egress policy.
B) Queue 2, because it is explicitly configured in the queue-group template.
C) The default, queue 1, because there is a mismatch between the mapping in the SAP-egress policy and in the queue-group template.
D) AF traffic is dropped because there is a mismatch between the mapping in the SAP-egress policy and in the queue-group template.

Question 27

Which of the following about a Nokia 7750 SR MP-BGP update is FALSE? Assume default behavior.

A) An MP-BGP update carries an MPLS label that is used as the service label for a VPRN.
B) There can be multiple Route Targets per route in an MP-BGP update.
C) There can only be one Route Distinguisher per route in an MP-BGP update.
D) On a specific PE, the MP-BGP updates for prefixes from a single VPRN carry different labels.
E) Traditional BGP attributes and MP-BGP attributes are present in an MP-BGP update.

Question 28

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

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 29

For the inter-AS model A VPRN, BGP is used as the PE-CE routing protocol. Which of the following statements about the control plane operation is TRUE?

A) PE1 sends an IPv4 update for prefix 192.168.1.0/27 via MP-BGP to ASBR1.
B) ASBR1 sends an IPv4 update for prefix 192.168.1.0/27 ASBR2.
C) ASBR1 transforms an IPv4 update for prefix 192.168.1.0/27 to a VPN-IPv4 route and allocates VPN label V1 and sends the update to ASBR2.
D) ASBR2 accepts a VPN-IPv4 update from ASBR1, then sends the update to PE2 via MP-BGP.

Question 30

Which of the following statements about a Management VPLS is TRUE?

A) Operates in transparent mode.
B) Inherits SAP and SDP state from uVPLS.
C) Does not carry customer traffic.
D) Runs one instance of RSTP per VPLS.

Question 31

The following VPLS services have been configured. Which of the following statements is TRUE?

A) All untagged frames will be forwarded to VPLS 1.
B) All frames with more than one VLAN tag will be dropped.
C) A frame with an outer VLAN tag of 300 and inner VLAN tag of 100 will be forwarded to VPLS 2.
D) A frame with a single VLAN tag of 500 will be forwarded to VPLS 1.
E) A frame with an outer VLAN tag of 500 and inner VLAN tag of 300 will be forwarded to VPLS 3.

Question 32

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?

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

Question 33

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

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

Question 34

What is PBB also known as?

A) H-VPLS
B) IEEE 802.1ag
C) MAC aggregation
D) MAC-in-MAC

Question 35

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

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 36

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

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.

Question 37

How is MAC learning achieved in traditional Ethernet switches?

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.