[2025年更新]合格できるJuniper JN0-280試験最新187問題 [Q98-Q114]

[2025年更新]合格できるJuniper JN0-280試験最新187問題

ゲット2025年最新の無料Juniper JN0-280試験問題アンサー

質問 # 98
You are configuring an aggregate route. In this scenario, which two statements are correct? (Choose two.)

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

正解：A、D

解説：
When configuring anaggregate 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:discardandreject.
Step-by-Step Breakdown:
* Discard:
* Thediscardoption will silently drop packets that match the aggregate route. No notification is sent to the sender, and the packet is simply dropped.
* Reject:
* Therejectoption will drop the packet and also send anICMP Destination Unreachablemessage 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.

質問 # 99
A routing policy has been created to advertise OSPF routes in BGP. Which statement is correct in this scenario?

A. Apply the policy as an import policy within OSPF.
B. Apply the policy as an import policy within BGP.
C. Apply the policy as an export policy within OSPF.
D. Apply the policy as an export policy within BGP.

正解：D

解説：
When advertisingOSPF routesintoBGP, the appropriaterouting policyshould be applied as anexport policy in BGP.
Step-by-Step Breakdown:
* OSPF to BGP Route Advertisement:Routes learned via OSPF (a dynamic IGP) need to be exported into BGP to be advertised to external BGP peers. In Junos OS, this is done usingexport policies.
* Export Policies in BGP:An export policy controls which routes are advertised out of a BGP session. In this scenario, the routing policy must be applied toBGP as an export policyto export the OSPF-learned routes to external BGP peers.
* Policy Configuration:Example configuration:
set policy-options policy-statement EXPORT_OSPF term 1 from protocol ospf set policy-options policy-statement EXPORT_OSPF term 1 then accept set protocols bgp group <group-name> export EXPORT_OSPF This policy ensures that only OSPF routes are exported into BGP.
Juniper Reference:
* Routing Policy: Export policies are used in BGP to control route advertisements to peers, including those learned via OSPF.

質問 # 100
When using spine and leaf fabric architectures, what is the role of each device? (Choose two.)

A. Leaf nodes are used for traffic to other leafs.
B. Spine nodes are used for transit to other leaf nodes.
C. Spine nodes are used for host connectivity.
D. Leaf nodes are used for host connectivity.

正解：B、D

解説：
In aspine-leaf fabric architecture, which is commonly used in data center designs, each device has a distinct role to ensure efficient and scalable network traffic flow.
Step-by-Step Breakdown:
* Spine Nodes:
* Thespine nodesform the backbone of the fabric and are responsible fortransit traffic between leaf nodes. They connect to every leaf switch and provide multiple paths for traffic between leaf nodes, ensuring redundancy and load balancing.
* Leaf Nodes:
* Theleaf nodesare used forhost connectivity. These switches connect to servers, storage, or edge routers. They also connect to the spine switches to reach other leaf switches.
Juniper Reference:
* Spine-Leaf Architecture: In Juniper's IP fabric designs,spine switcheshandle inter-leaf communication, whileleaf switchesmanage host and endpoint connectivity.

質問 # 101
Referring to the exhibit, which statement is correct?

A. The ge-0/0/12 interfaces is an access port.
B. The ge-0/0/0 interface has been explicitly assigned to a VLAN named default.
C. The asterisk indicates that the interface is active.
D. The default VLAN is a user defined VLAN name.

正解：C

質問 # 102
Which statement is correct about the OSPF link-state database?

A. Each router within the OSPF domain must maintain an identical copy of the link-state database.
B. Each router within the OSPF domain must maintain a unique copy of the link-state database.
C. Each router within the same area must maintain a unique copy of the link-state database.
D. Each router within the same area must maintain an identical copy of the link-state database.

正解：D

質問 # 103
How does VLAN tagging benefit network segmentation?

A. By enabling the identification and separation of traffic belonging to different VLANs.
B. By providing a backup path for data in case of link failure.
C. By encrypting data traffic between VLANs.
D. By ensuring the same IP address range can be used in different VLANs.

正解：A

質問 # 104
Referring to the exhibit, which two statements are correct about the IP fabric? (Choose two.)

A. Only traffic between pods must traverse the super spine devices.
B. This is a three-stage IP fabric.
C. This is a five-stage fabric.
D. All traffic must traverse the super spine devices.

正解：A、C

質問 # 105
Which operation mode command will display the mapping between the VLAN ID and ports on a switch?

A. show vlans
B. show interfaces terse
C. show route
D. show ethernet-switching table

正解：A

解説：
To display themapping between VLAN IDs and portson a Juniper switch, the show vlans command is used.
Step-by-Step Breakdown:
* VLAN Information:The show vlans command displays detailed information about VLAN configurations, including the VLAN ID, associated interfaces (ports), and VLAN membership.
* Command Example:
show vlans
* This command will provide an output listing each VLAN, its ID, and the interfacesassociated with the VLAN, enabling network engineers to quickly verify VLAN to port mappings.
Juniper Reference:
* VLAN Verification: Use the show vlans command to verify which VLANs are configured on the switch and the ports that are members of those VLANs.

質問 # 106
When evaluating BGP routes, what will be evaluated first?

A. The origin value
B. The local preference value
C. The MED value
D. The AS path

正解：B

解説：
InBGP (Border Gateway Protocol), when evaluating multiple routes to the same destination, the first attribute that is considered is thelocal preferencevalue. Thelocal preferenceis a BGP attribute used to influence outbound routing decisions within an Autonomous System (AS).
Step-by-Step Breakdown:
* Local Preference:Thelocal preferenceattribute is used to determine which path is preferred for traffic leaving the AS. The higher the local preference value, the more preferred the route.
* BGP Path Selection:The BGP path selection process evaluates the following attributes in this order:
* Local Preference(higher is preferred)
* AS Path(shorter is preferred)
* Origin(IGP > EGP > incomplete)
* MED (Multi-Exit Discriminator)(lower is preferred)
Juniper Reference:
* BGP Path Selection: In Junos, thelocal preferenceattribute is the first to be evaluated when determining the best path for outbound traffic.

質問 # 107
Which two statements are true with regards to MACsec?

A. It does not provide authentication for an Ethernet traffic between two network nodes.
B. It does not provide encryption for an Ethernet traffic between two network nodes.
C. It provides authentication for an Ethernet traffic between two network nodes.
D. It provides encryption for an Ethernet traffic between two network nodes.

正解：C、D

質問 # 108
During a BGP Graceful Restart, what happens to the routes learned from the restarting neighbor?

A. They are advertised to other BGP neighbors.
B. They are immediately removed from the routing table.
C. Their metric is increased to prevent their use.
D. They are marked as stale but kept in the routing table.

正解：D

質問 # 109
What is the default route preference of a static route in the Junos OS?

A. 0
B. 1
C. 2
D. 3

正解：C

解説：
In Junos OS, the default route preference for a static route is 5. Route preference values are used to determine which route should be installed in the routing table when multiple routes to the same destination are available.
Step-by-Step Breakdown:
Static Route Preference:
A static route, by default, has a preference of 5, making it a highly preferred route. Lower preference values are more preferred in Junos, meaning static routes take precedence over most dynamic routing protocol routes, such as OSPF (preference 10) or BGP (preference 170).
Route Preference:
Route preference is a key factor in the Junos routing decision process. Routes with lower preference values are preferred and installed in the forwarding table.
Juniper Reference:
Static Routes: In Junos, the default preference for static routes is 5, making them more preferred than most dynamic routes.

質問 # 110
What are two characteristics of a typical EBGP underlay fabric? (Choose two.)

A. Each device in an EBGP fabric will be configured in its own unique private AS.
B. Each device in an EBGP fabric will be configured to be part of the same private AS.
C. An EBGP fabric relies on an IGP to advertise loopback IPs.
D. An EBGP fabric does not require an IGP to advertise loopback IPs.

正解：A、D

質問 # 111
When configuring OSPF, what is the purpose of defining areas?