Juniper JN0-280 Online Practice Questions and Exam Preparation

Juniper JN0-280 Online Questions & Answers

• Question 131:

  What is the primary function of a VLAN?

  A. To encrypt network traffic.
  B. To provide a routing mechanism between different networks.
  C. To segment a network into multiple broadcast domains.
  D. To control network traffic based on MAC addresses.
  C. To segment a network into multiple broadcast domains.

• Question 132:

  When troubleshooting issues with static routes, what is a key factor to check first?

  A. If the routing table has enough memory
  B. The correctness of the specified next-hop addresses
  C. The speed of the router's CPU
  D. The number of aggregate routes configured
  B. The correctness of the specified next-hop addresses

• Question 133:

  Which signaling protocol is used for EVPN?

  A. OSPF
  B. PIM
  C. IS-IS
  D. BGP
  D. BGP

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  Explanation/Reference:

  EVPN (Ethernet Virtual Private Network)is a standard protocol used for building Layer 2 and Layer 3 VPNs over an IP or MPLS network. The signaling protocol used for EVPN is BGP (Border Gateway Protocol).

  Step-by-Step Breakdown:

  BGP as the EVPN Signaling Protocol:EVPN uses BGP to exchange MAC address reachability information between routers (PE devices). This enables devices to learn which MAC addresses are reachable through which PE devices,

  facilitating Layer 2 forwarding across an IP or MPLS core.

  BGP Extensions for EVPN:BGP is extended with new address families (e.g., EVPN NLRI) to carry both MAC and IP address information, allowing for scalable and efficient multi-tenant network solutions.

  Juniper Reference:

  Junos EVPN Configuration: Juniper uses BGP as the control plane for EVPN to exchange MAC and IP route information between different data center devices.

• Question 134:

  Referring to the exhibit, which statement is correct?

  

  A. The configuration will commit successfully and BGP group 1 will operate as IBGP.
  B. The configuration will commit successfully and BGP group 1 will operate as EBGP.
  C. BGP group 1 requires a type external parameter.
  D. BGP group 1 requires a type internal parameter.
  B. The configuration will commit successfully and BGP group 1 will operate as EBGP.

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  Explanation/Reference:

  In the exhibit, BGP is configured with local AS 65101 and a neighbor at 172.16.1.1 peer AS 65201 in . This setup involves two different Autonomous Systems (AS), indicating an External BGP (EBGP) configuration.

  Step-by-Step Breakdown:

  EBGP vs. IBGP:

  EBGPis used between routers in different ASes. In this case, the local AS is 65101 and the peer AS is 65201 , meaning the BGP session is EBGP .

  IBGPis used between routers within the same AS, which is not applicable here as the AS numbers are different.

  BGP Group Configuration:

  The configuration does not require a type external parameter because Junos OSautomatically recognizes the session as EBGP when the local and peer AS numbers are different.

  The BGP session will operate as EBGP, and the configuration will commit successfully.

  Juniper Reference:

  BGP Configuration: In Juniper, EBGP is automatically recognized when the local and peer AS numbers differ, without needing to specify type external.

• Question 135:

  You are configuring an aggregate route. In this scenario, which two statements are correct? (Choose two.)

  A. Reject will silently drop the traffic.
  B. Discard will silently drop the traffic.
  C. Reject will send an ICMP Destination Unreachable message back to the sender.
  D. Discard will send an ICMP Destination Unreachable message back to the sender.
  B. Discard will silently drop the traffic.
  C. Reject will send an ICMP Destination Unreachable message back to the sender.

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  Explanation/Reference:

  When configuring an aggregate route , you have options for how to handle traffic that matches the route but does not match any more specific route in the routing table. Two actions can be taken: discard and reject .

  Step-by-Step Breakdown:

  Discard:

  The discard option will silently drop packets that match the aggregate route. No notification is sent to the sender, and the packet is simply dropped.

  Reject:

  The reject option will drop the packet and also send an ICMP Destination Unreachable message back to the sender. This informs the sender that the packet could not be delivered because there is no specific route available.

  Juniper Reference:

  Aggregate Routes: The reject and discard next-hop options provide different levels of feedback when packets cannot be routed, and they can be used to control how unreachable destinations are handled.