Juniper JN0-664 Online Practice Questions and Exam Preparation

Juniper JN0-664 Online Questions & Answers

• Question 71:

  Referring to the exhibit

  

  You are examining an L3VPN route that includes the information shown in the exhibit Which statement is correct in this scenario?

  A. The information shows a Type 1 route distinguisher.
  B. The information shows a Type 0 route distinguisher
  C. The information shows a Type 2 route distinguisher.
  D. The information shows a route target
  A. The information shows a Type 1 route distinguisher.

  ---

  Explanation/Reference:

• Question 72:

  You are configuring a BGP signaled Layer 2 VPN across your MPLS enabled core network. Your PE-2 device connects to two sites within the s VPN

  In this scenario, which statement is correct?

  A. By default on PE-2, the site's local ID is automatically assigned a value of 0 and must be configured to match the total number of attached sites.
  B. You must create a unique Layer 2 VPN routing instance for each site on the PE-2 device.
  C. You must use separate physical interfaces to connect PE-2 to each site.
  D. By default on PE-2, the remote site IDs are automatically assigned based on the order that you add the interfaces to the site configuration.
  D. By default on PE-2, the remote site IDs are automatically assigned based on the order that you add the interfaces to the site configuration.

  ---

  Explanation/Reference:

  BGP Layer 2 VPNs use BGP to distribute endpoint provisioning information and set up pseudowires between PE devices. BGP uses the Layer 2 VPN (L2VPN) Routing Information Base (RIB) to store endpoint provisioning information, which is updated each time any Layer 2 virtual forwarding instance (VFI) is configured. The prefix and path information is stored in the L2VPN database, which allows BGP to make decisions about the best path. In BGP Layer 2 VPNs, each site has a unique site ID that identifies it within a VFI. The site ID can be manually configured or automatically assigned by the PE device. By default, the site ID is automatically assigned based on the order that you add the interfaces to the site configuration. The first interface added to a site configuration has a site ID of 1, the second interface added has a site ID of 2, and so on. Option D is correct because by default on PE-2, the remote site IDs are automatically assigned based on the order that you add the interfaces to the site configuration. Option A is not correct because by default on PE-2, the site's local ID is automatically assigned a value of 0 and does not need to be configured to match the total number of attached sites. Option B is not correct because you do not need to create a unique Layer 2 VPN routing instance for each site on the PE-2 device. You can create one routing instance for all sites within a VFI. Option C is not correct because you do not need to use separate physical interfaces to connect PE-2 to each site. You can use subinterfaces or service instances on a single physical interface.

• Question 73:

  Referring to the exhibit Which two statements are correct regarding the output shown in the exhibit? (Choose two.)

  

  A. The multicast group is an ASM group.
  B. The multicast group is an SSM group.
  C. The multicast traffic is using the SPT.
  D. The multicast traffic is using the RPT.
  B. The multicast group is an SSM group.
  C. The multicast traffic is using the SPT.

  ---

  Explanation/Reference:

• Question 74:

  Referring to the exhibit.

  

  You are attempting to summarize routes from the 203.0.113.128/25 IP block on R8 to AS 64500. You implement the export policy shown in the exhibit and all routes from the routing table stop being advertised. In this scenario, which two steps would you take to summarize the route in BGP? (Choose two.)

  A. Remove the from protocol bgp command from the export policy.
  B. Add the set protocols bgp family inet unicast add-path command to allow additional routes to the RIB tables.
  C. Add the set routing-options static route 203.0.113.123/25 discard command.
  D. Replace exact in the export policy with orlonger.
  C. Add the set routing-options static route 203.0.113.123/25 discard command.
  D. Replace exact in the export policy with orlonger.

  ---

  Explanation/Reference:

  To summarize routes from the 203.0.113.128/25 IP block on R8 to AS 64500, you need to do the following:

  Add the set routing-options static route 203.0.113.128/25 discard command. This creates a static route for the summary prefix and discards any traffic destined to it. This is necessary because BGP can only advertise routes that are present in

  the routing table.

  Replace exact in the export policy with orlonger. This allows R8 to match and advertise any route that is equal or more specific than the summary prefix. The exact term only matches routes that are exactly equal to the summary prefix, which

  is not present in the routing table.

• Question 75:

  A packet is received on an interface configured with transmission scheduling. One of the configured queues In this scenario, which two actions will be taken by default on a Junos device? (Choose two.)

  A. The excess traffic will be discarded
  B. The exceeding queue will be considered to have negative bandwidth credit.
  C. The excess traffic will use bandwidth available from other queueses
  D. The exceeding queue will be considered to have positive bandwidth credit
  B. The exceeding queue will be considered to have negative bandwidth credit.
  C. The excess traffic will use bandwidth available from other queueses

  ---

  Explanation/Reference:

• Question 76:

  Referring to the exhibit.

  

  Click the Exhibit button-Referring to the exhibit, which two statements are correct about BGP routes on R3 that are learned from the ISP-A neighbor? (Choose two.)

  A. By default, the next-hop value for these routes is not changed by ISP-A before being sent to R3.
  B. The BGP local-preference value that is used by ISP-A is not advertised to R3.
  C. All BGP attribute values must be removed before receiving the routes.
  D. The next-hop value for these routes is changed by ISP-A before being sent to R3.
  B. The BGP local-preference value that is used by ISP-A is not advertised to R3.
  D. The next-hop value for these routes is changed by ISP-A before being sent to R3.

  ---

  Explanation/Reference:

• Question 77:

  Click the Exhibit button.

  

  Which two statements are correct about the class-of-service configuration shown in the exhibit? (Choose two.)

  A. Incoming traffic will be classified using the default classifier.
  B. The best-effort queue can never transmit more than 40% of the total bandwidth on the ge-0/0/0 interface, even if that bandwidth is available.
  C. Incoming traffic will not be classified because no classifier exists in the configuration.
  D. The best-effort queue can transmit more than 40% of the total bandwidth on the ge-0/0/0 interface, if no other queue is using that bandwidth.
  A. Incoming traffic will be classified using the default classifier.
  D. The best-effort queue can transmit more than 40% of the total bandwidth on the ge-0/0/0 interface, if no other queue is using that bandwidth.

  ---

  Explanation/Reference:

• Question 78:

  Which two statements are correct regarding the PIM DR in a PIM-SM domain? (Choose two.)

  A. By default. PIM DR election is performed on point-to-point links.
  B. If the DR priorities match, the router with the lowest IP address is selected as the DR.
  C. The source DR sends PIM register messages from the source network to the RP.
  D. The receiver DR sends PIM join and PIM prune messages from the receiver network toward the RP.
  C. The source DR sends PIM register messages from the source network to the RP.
  D. The receiver DR sends PIM join and PIM prune messages from the receiver network toward the RP.

  ---

  Explanation/Reference:

• Question 79:

  Referring to the exhibit.

  

  Which two statements are correct about the class-of-service configuration shown in the exhibit? (Choose two.)

  A. The drop probability jumps immediately from 20% to 60% when the queue level reaches 75% full.
  B. The drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to 75% full
  C. To use this drop profile, you reference it in a scheduler.
  D. To use this drop profile, you apply it directly to an interface.
  B. The drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to 75% full
  C. To use this drop profile, you reference it in a scheduler.

  ---

  Explanation/Reference:

  class-of-service (CoS) is a feature that allows you to prioritize and manage network traffic based on various criteria, such as application type, user group, or packet loss priority. CoS uses different components to classify, mark, queue, schedule, shape, and drop traffic according to the configured policies. One of the components of CoS is drop profiles, which define how packets are dropped when a queue is congested. Drop profiles use random early detection (RED) algorithm to drop packets randomly before the queue is full, which helps to avoid global synchronization and improve network performance. Drop profiles can be discrete or interpolated. A discrete drop profile maps a specific fill level of a queue to a specific drop probability. An interpolated drop profile maps a range of fill levels of a queue to a range of drop probabilities and interpolates the values in between. In the exhibit, we can see that the class-of-service configuration shows an interpolated drop profile with two fill levels (50 and 75) and two drop probabilities (20 and 60). Based on this configuration, we can infer the following statements: The drop probability jumps immediately from 20% to 60% when the queue level reaches 75% full. This is not correct because the drop profile is interpolated, not discrete. This means that the drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to 75% full. The drop probability for any fill level between 50% and 75% can be calculated by using linear interpolation formula. The drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to 75% full. This is correct because the drop profile is interpolated and uses linear interpolation formula to calculate the drop probability for any fill level between 50% and 75%. For example, if the fill level is 60%, the drop probability is 28%, which is calculated by using the formula: (60 - 50) / (75 -50) * (60 - 20) + 20 = 28. To use this drop profile, you reference it in a scheduler. This is correct because a scheduler is a component of CoS that determines how packets are dequeued from different queues and transmitted on an interface. A scheduler can reference a drop profile by using the random-detect statement under the [edit class-of-service schedulers] hierarchy level. For example: scheduler test { transmit-rate percent 10; buffer-size percent 10; random-detect test-profile; } To use this drop profile, you apply it directly to an interface. This is not correct because a drop profile cannot be applied directly to an interface. A drop profile can only be referenced by a scheduler, which can be applied to an interface by using the scheduler-map statement under the [edit class-of-service interfaces] hierarchy level. For example: interfaces ge-0/0/0 { unit 0 { scheduler-map test-map; } }

• Question 80:

  Which two EVPN route types are used to advertise a multihomed Ethernet segment? (Choose two )

  A. Type 1
  B. Type 3
  C. Type 4
  D. Type 2
  A. Type 1
  C. Type 4

  ---

  Explanation/Reference:

  EVPN is a solution that provides Ethernet multipoint services over MPLS networks. EVPN uses BGP to distribute endpoint provisioning information and set up pseudowires between PE devices. EVPN uses different route types to convey

  different information in the control plane. The following are the main EVPN route types:

  Type 1 - Ethernet Auto-Discovery Route: This route type is used for network-wide messaging and discovery of other PE devices that are part of the same EVPN instance. It also carries information about the redundancy mode and load

  balancing algorithm of the PE devices.

  Type 2 - MAC/IP Advertisement Route: This route type is used for MAC and IP address learning and advertisement between PE devices. It also carries information about the Ethernet segment identifier (ESI) and the label for forwarding traffic

  to the MAC or IP address.

  Type 3 - Inclusive Multicast Ethernet Tag Route: This route type is used for broadcast, unknown unicast, and multicast (BUM) traffic forwarding. It also carries information about the multicast group and the label for forwarding BUM traffic. Type 4 - Ethernet Segment Route: This route type is used for multihoming scenarios, where a CE device is connected to more than one PE device. It also carries information about the ESI and the designated forwarder (DF) election process.