Juniper JN0-351リアル試験問題テストエンジン問題集トレーニングには67問あります [Q36-Q55]

Juniper JN0-351リアル試験問題テストエンジン問題集トレーニングには67問あります

JN0-351実際の問題解答PDFには100%カバー率リアル試験問題

質問 # 36
What are two characteristics of RSTP alternate ports? (Choose two.)

A. RSTP alternate ports provide an alternate lower cost path to the root bridge.
B. RSTP alternate ports provide an alternate higher cost path to the root bridge.
C. RSTP alternate ports block traffic while receiving superior BPDUs from a neighboring switch.
D. RSTP alternate ports are active ports used to forward frames toward the root bridge.

正解：B、C

解説：
A is correct because RSTP alternate ports block traffic while receiving superior BPDUs from a neighboring switch. An alternate port is a backup port for a root port, which means it receives better BPDUs from another bridge than the current root port1. However, an alternate port does not forward any traffic, as it is in a discarding state2. It only listens to BPDUs and waits for the root port to fail. If the root port fails, the alternate port can immediately transition to a forwarding state and become the new root port1.
C is correct because RSTP alternate ports provide an alternate higher cost path to the root bridge. An alternate port is selected based on the same criteria as the root port, which are the lowest bridge ID, the lowest path cost, the lowest sender port ID, and the lowest receiver port ID3. However, an alternate port receives a higher cost BPDU than the root port, otherwise it would be the root port itself1. Therefore, an alternate port provides an alternate higher cost path to the root bridge than the root port.

質問 # 37
You need to configure a LAG between your switches. In this scenario, which two statements are correct?
(Choose two.)

A. Duplex and speed settings are required to match on both participating devices.
B. Member links are required to be contiguous ports.
C. Member links are not required to be contiguous ports.
D. Duplex and speed settings are not required to match on both participating devices.

正解：A、C

解説：
B is correct because duplex and speed settings are required to match on both participating devices. According to the Juniper Networks documentation1, all the interfaces in a LAG must have the same speed and be in full-duplex mode. This ensures that the LAG can operate as a single logical link without any performance or compatibility issues.
C is correct because member links are not required to be contiguous ports. According to the Juniper Networks documentation2, you can group any Ethernet interfaces on a switch into a LAG, regardless of their physical location or slot number. This provides flexibility and scalability for configuring LAGs on switches.

質問 # 38
You deployed a new EX Series switch with DHCP snooping enabled and you do not see any entries in the snooping databases for an interface. Which two Juniper configurations for that interface caused this issue?
(Choose two.)

A. MAC limiting is enabled on the interface.
B. The interface is configured as a trunk port.
C. Dynamic ARP inspection is enabled on the interface.
D. The interface is configured as a disabled port.

正解：B、D

解説：
A is correct because the interface is configured as a disabled port. A disabled port does not forward any traffic, including DHCP packets. Therefore, DHCP snooping cannot learn any MAC addresses or lease information from a disabled port1.
C is correct because the interface is configured as a trunk port. By default, all trunk ports on the switch are trusted for DHCP snooping2. This means that DHCP snooping does not inspect or filter any DHCP packets received on a trunk port. Therefore, DHCP snooping does not add any entries to the snooping database for a trunk port2.

質問 # 39
A new network requires multiple topology support. You decide to use IS-IS in this situation. Which three protocol topologies are supported in this scenario? (Choose three.)

A. IPsec
B. multicast
C. anycast
D. IPv4
E. IPv6

正解：B、D、E

解説：
Explanation
IS-IS (Intermediate System to Intermediate System) is a routing protocol that is designed to move information efficiently within a computer network12. It supports multiple protocol topologies, including IPv4, IPv6, and multicast12. Therefore, options C, E, and D are correct.

質問 # 40
Exhibit.

You have configured the four EX Series switches with RSTP, as shown in the exhibit. You discover that whenever a link between switches goes up or down, the switches take longer than expected for RSTP to converge, using the default settings.
In this scenario, which action would solve the delay in RSTP convergence?

A. The hello-time must be increased.
B. The force-version must be removed.
C. The bridge priority for EX-4 must be set at 4000.
D. The max-age must be increased to 20

正解：B

解説：
The exhibit shows the configuration of RSTP on EX-4, which has the command force-version stp. This command forces the switch to use the legacy STP protocol instead of RSTP, even though the switch supports RSTP1. This means that EX-4 will not be able to take advantage of the faster convergence and enhanced features of RSTP, such as edge ports, link type, and proposal/agreement sequence2.
The other switches in the network are likely to be running RSTP, as it is the default protocol for EX Series switches3. Therefore, there will be a compatibility issue between EX-4 and the other switches, which will result in longer convergence times and suboptimal performance. The switch will also generate a warning message that says "Warning: STP version mismatch with neighbor" when it receives a BPDU from a RSTP neighbor1.
To solve this problem, the force-version command must be removed from EX-4, so that it can run RSTP natively and interoperate with the other switches in the network. This will enable faster convergence and better stability for the network topology. To remove the command, you can use the delete protocols rstp force-version command in configuration mode1.

質問 # 41
Refer to the exhibit.

Referring to the output shown in the exhibit, which statement is correct?

A. An area ID mismatch exists between the OSPF neighbors
B. An MTU mismatch exists between the OSPF neighbors.
C. The state is normal for a DR neighbor.
D. The state is normal for a DRother neighbor

正解：D

解説：
Explanation
In OSPF, the state of the neighbor relationship is determined by the exchange of OSPF packets between routers1. The state "2Way" as shown in the exhibit indicates that bi-directional communication has been established between the two OSPF routers1. This is the normal state for a neighbor that is not the Designated Router (DR) or Backup Designated Router (BDR) on a broadcast, non-broadcast multi-access (NBMA), or point-to-multipoint network1. These neighbors are often referred to as "DRothers"1. Therefore, option B is correct.

質問 # 42
Exhibit

Referring to the exhibit, which statement is correct?

A. The root bridge is using a bridge priority of 4k.
B. The local device is the root bridge for this RSTP topology.
C. The local device is using a bridge priority of 4k.
D. The root bridge has not been elected for this RSTP topology.

正解：B

解説：
Explanation
In a Rapid Spanning Tree Protocol (RSTP) topology, the root bridge is determined by the switch with the lowest bridge priority value12. If all switches have the same priority, then the root bridge is assigned to the switch whose MAC address's hex value is the lowest2. The default bridge priority value is 3276832. However, without the actual exhibit, it's difficult to definitively determine which device is the root bridge. But based on the options provided, if we assume that the local device has a lower bridge priority or a lower MAC address than other devices in the network, then it could be considered as the root bridge for this RSTP topology45.

質問 # 43
In RSTP, which three port roles are associated with the discarding state? (Choose three.)

A. disabled
B. designated
C. backup
D. root
E. alternate

正解：A、C、E

解説：
Explanation
In Rapid Spanning Tree Protocol (RSTP), there are several port roles that determine the behavior of the port in the spanning tree123. The roles include root, designated, alternate, backup, and disabled123.
The discarding state is associated with the backup, alternate, and disabled roles123. In a stable topology with consistent port roles throughout the network, RSTP ensures that every root port and designated port immediately transition to the forwarding state while all alternate and backup ports are always in the discarding state2. Disabled ports are also in the discarding state3.
Therefore, options B, C, and D are correct.

質問 # 44
You are attempting to configure the initial two aggregated Ethernet interfaces on a router but there are no aggregated Ethernet interfaces available.
In this scenario, which configuration will enable these interfaces on this router?

正解：A

解説：
Explanation
The correct answer to your question is
Option C shows the configuration of the statement, which defines the properties of the router chassis, such as the number of aggregated Ethernet interfaces, the number of FPCs, and the number of PICs1.
To enable aggregated Ethernet interfaces on a router, you need to specify the aggregated-devices statement under the chassis parameter to the desired number of interfaces2. For example, to enable two aggregated Ethernet interfaces, you can use the following configuration:
chassis { aggregated-devices { ethernet { device-count 2; } } }
Option C shows this configuration with the device-count set to 2, which will enable two aggregated Ethernet interfaces on the router. The other options do not show this configuration and will not enable any aggregated Ethernet interfaces on the router.
Therefore, option C is the correct answer to your question.

質問 # 45
Exhibit.

You want to verify prefix information being sent from 10.36.1.4.
Which two statements are correct about the output shown in the exhibit? (Choose two.)

A. The routes displayed are being learned from an I BGP peer.
B. The output shows routes that were received prior to the application of any BGP import policies.
C. The routes displayed have traversed one or more autonomous systems.
D. The output shows routes that are active and rejected by an import policy.

正解：B、C

解説：
Explanation
The output shown in the exhibit is the result of the command "show ip bgp neighbor 10.36.1.4 received-routes", which displays all received routes (both accepted and rejected) from the specified neighbor.
Option A is correct, because the routes displayed have traversed one or more autonomous systems. This can be seen from the AS_PATH attribute, which shows the sequence of AS numbers that the route has passed through. For example, the route 10.0.0.0/8 has an AS_PATH of 65001 65002, which means that it has traversed AS 65001 and AS 65002 before reaching the local router.
Option B is correct, because the output shows routes that were received prior to the application of any BGP import policies. This can be seen from the fact that some routes have a status code of "r", which means that they are rejected by an import policy. The"received-routes" keyword shows the routes coming from a given neighbor before the inbound policy has been applied. To see the routes after the inbound policy has been applied, the "routes" keyword should be used instead.
Option C is incorrect, because the output does not show routes that are active and rejected by an import policy.
The status code of "r" means that the route is rejected by an import policy, but it does not mean that it is active. The status code of ">" means that the route is active and selected as the best path. None of the routes in the output have both ">" and "r" status codes.
Option D is incorrect, because the routes displayed are not being learned from an IBGP peer. An IBGP peer is a BGP neighbor that belongs to the same AS as the local router. The output shows that the neighbor 10.36.1.4 has a remote AS of 65001, which is different from the local AS of 65002. Therefore, the neighbor is an EBGP peer, not an IBGP peer.

質問 # 46
Exhibit.

Which router will become the OSPF BDR if all routers are powered on at the same time?

A. R2
B. R4
C. R1
D. R3

正解：B

解説：
Explanation
OSPF DR/BDR election is a process that occurs on multi-access data links. It is intended to select two OSPF nodes: one to be acting as the Designated Router (DR), and another to be acting as the Backup Designated Router (BDR).The DR and BDR are responsible for generating network LSAs for the multi-access network and synchronizing the LSDB with other routers on the same network1.
The DR/BDR election is based on two criteria: the OSPF priority and the router ID. The OSPF priority is a value between 0 and 255 that can be configured on each interface participating in OSPF. The default priority is
1. A priority of 0 means that the router will not participate in the election and will never become a DR or BDR. The router with the highest priority will become the DR, and the router with the second highest priority will become the BDR. If there is a tie in priority, then the router ID is used as a tie-breaker. The router ID is a
32-bit number that uniquely identifies each router in an OSPF domain.It can be manually configured or automatically derived from the highest IP address on a loopback interface or any active interface2.
In this scenario, all routers have the same priority of 1, so the router ID will determine the outcome of the election. The router IDs are shown in the exhibit as RID values. The highest RID belongs to R4 (10.10.10.4), so R4 will become the DR. The second highest RID belongs to R3 (10.10.10.3), so R3 will become the BDR.
References:
1:OSPF DR/BDR Election: Process, Configuration, and Tuning2:OSPF Designated Router (DR) and Backup Designated Router (BDR)

質問 # 47
What is the default keepalive time for BGP?

A. 90 seconds
B. 60 seconds
C. 30 seconds
D. 10 seconds

正解：B

解説：
Explanation
The default keepalive time for BGP is 60 seconds1. The keepalive time is the interval at which BGP sends keepalive messages to maintain the connection with its peer1. If the keepalive message is not received within the hold time, the connection is considered lost1. By default, the hold time is three times the keepalive time, which is 180 seconds1.

質問 # 48
Exhibit.

The ispi _ inet. 0 route table has currently no routes in it.
What will happen when you commit the configuration shown on the exhibit?

A. The inet. 0 route table will be imported into the ispi . inet. 0 route table.
B. The inet. 0 route table will be completely overwritten by the ispi . inet. 0 route table.
C. The ISPI . inet. 0 route table will be imported into the inet. 0 route table.
D. The ISPI . inet. 0 route table will be completely overwritten by the inet. o route table.

正解：A

解説：
Explanation
The configuration shown in the exhibit is an example of a routing instance of type virtual-router. A routing instance is a collection of routing tables, interfaces, and routing protocol parameters that create a separate routing domain on a Juniper device1. A virtual-router routing instance allows administrators to divide a device into multiple independent virtual routers, each with its own routing table2.
The configuration also includes a rib-group statement, which is used to import routes from one routing table to another. A rib-group consists of an import-rib statement, which specifies the source routing table, and an export-rib statement, which specifies the destination routing table.
In this case, the rib-group name is inet-to-ispi, and the import-rib statement specifies inet.0 as the source routing table. The export-rib statement specifies ispi.inet.0 as the destination routing table. This means that the routes from inet.0 will be imported into ispi.inet.0.
Therefore, the correct answer is B. The inet.0 route table will be imported into the ispi.inet.0 route table.
References:
1: Routing Instances Overview 2: Virtual Routing Instances : [rib-group (Routing Options)]

質問 # 49
Exhibit.

You are using OSPF to advertise the subnets that are used by the Denver and Dallas offices. The routers that are directly connected to the Dallas and Denver subnets are not advertising the connected subnets.
Referring to the exhibit, which two statements are correct? (Choose two.)

A. Configure and apply a routing policy that redistributes the Dallas and Denver subnets using Type 5 LSAs.
B. Enable the passive option on the OSPF interfaces that are connected to the Dallas and Denver subnets.
C. Configure and apply a routing policy that redistributes the connected Dallas and Denver subnets.
D. Create static routes on the switches using the local vMX router's loopback interface for the next hop.

正解：B、C

解説：
Explanation
The routers that are directly connected to the Dallas and Denver subnets are not advertising the connected subnets. This can be resolved by redistributing the connected subnets into OSPF1.
Option C suggests to configure and apply a routing policy that redistributes the connected Dallas and Denver subnets. This is correct because redistribution allows routes from one routing protocol to be communicated to another, and in this case, it allows the connected subnets to be advertised through OSPF1.
Option D suggests enabling the passive option on the OSPF interfaces that are connected to the Dallas and Denver subnets. This is also correct because in OSPF, a passive interface is an interface that belongs to the OSPF router, but does not send OSPF Hello packets1. It's typically used on an interface that you don't want to use for OSPF adjacencies, but you still want to advertise its IP address1. Therefore, enabling passive interface can help in advertising the Dallas and Denver subnets.

質問 # 50
Which two statements are correct about tunnels? (Choose two.)

A. Tunnels add additional overhead to packet size.
B. IP-IP tunnels are stateful.
C. BFD cannot be used to monitor tunnels.
D. Tunnel endpoints must have a valid route to the remote tunnel endpoint.

正解：A、D

解説：
Explanation
A tunnel is a connection between two computer networks, in which data is sent from one network to another through an encrypted link. Tunnels are commonly used to secure data communications between two networks or to connect two networks that use different protocols.
Option B is correct, because tunnel endpoints must have a valid route to the remote tunnel endpoint. A tunnel endpoint is the device that initiates or terminates a tunnel connection. For a tunnel to be established, both endpoints must be able to reach each other over the underlying network. This means that they must have a valid route to the IP address of the remote endpoint1.
Option D is correct, because tunnels add additional overhead to packet size. Tunnels work by encapsulating packets: wrapping packets inside of other packets. This means that the original packet becomes the payload of the surrounding packet, and the surrounding packet has its own header and trailer. The header and trailer of the surrounding packet add extra bytes to the packet size, which is called overhead. Overhead can reduce the efficiency and performance of a network, as it consumes more bandwidth and processing power2.
Option A is incorrect, because BFD can be used to monitor tunnels. BFD is a protocol that can be used to quickly detect failures in the forwarding path between two adjacent routers or switches. BFD can be integrated with various routing protocols and link aggregation protocols to provide faster convergence and fault recovery.
BFD can also be used to monitor the connectivity of tunnels, such as GRE, IPsec, or MPLS.
Option C is incorrect, because IP-IP tunnels are stateless. IP-IP tunnels are a type of tunnels that use IP as both the encapsulating and encapsulated protocol. IP-IP tunnels are simple and easy to configure, but they do not provide any security or authentication features. IP-IP tunnels are stateless, which means that they do not keep track of the state or status of the tunnel connection. Stateless tunnels do not require any signaling or negotiation between the endpoints, but they also do not provide any error detection or recovery mechanisms.
References:
1: What is Tunneling? | Tunneling in Networking 2: What Is Tunnel In Networking, Its Types, And Its Benefits? : [Configuring Bidirectional Forwarding Detection] : [IP-IP Tunneling]

質問 # 51
Which two statements are true about the default VLAN on Juniper switches? (Choose two.)

A. The default VLAN ID can be changed.
B. The default VLAN is set to a VLAN ID of 1 by default
C. The default VLAN ID is not assigned to any interface.
D. The default VLAN ID is not visible.

正解：A、B

解説：
Explanation
On Juniper switches, the default VLAN is set to a VLAN ID of 1 by default12. This means that all interfaces on the switch are members of VLAN 1 until they are specifically assigned to another VLAN12. Therefore, option A is correct.
The default VLAN ID can be changed12. This allows network administrators to configure the switch to use a different VLAN as the default, if necessary12. Therefore, option D is correct.

質問 # 52
Which two types of tunnels are able to be created on all Junos devices? (Choose two.)

A. IPsec
B. IP-IP
C. GRE
D. STP

正解：A、C

解説：
Explanation
Junos devices support various types of tunnels for different purposes12.
Option B is correct. Generic Routing Encapsulation (GRE) is a tunneling protocol that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links over an Internet Protocol network1. Junos devices support GRE tunnels1.
Option D is correct. IPsec (Internet Protocol Security) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session1. Junos devices support IPsec tunnels1.
Option A is incorrect. Spanning Tree Protocol (STP) is not a type of tunnel. It's a network protocol designed to prevent loops in a bridged Ethernet local area network2.
Option C is incorrect. While Junos devices do support IP-IP (also known as IP tunneling), it's not supported on all Junos devices1.

質問 # 53
What is the maximum allowable MTU size for a default GRE tunnel without IPv4 traffic fragmentation?

A. 1476 bytes
B. 1500 bytes
C. 1480 bytes
D. 1496 bytes

正解：A

解説：
Explanation
The maximum allowable MTU size for a default GRE tunnel without IPv4 traffic fragmentation is 1476 bytes1. This is because GRE packets are formed by the addition of the original packets and the required GRE headers1. These headers are 24-bytes in length and since these headers are added to the original frame, depending on the original size of the packet we may run into IP MTU problems1. The most common IP MTU is 1500-bytes in length (Ethernet)1. When the tunnel is created, it deducts the 24-bytes it needs to encapsulate the passenger protocols and that is the IP MTU it will use1. For example, if we are forming a tunnel over FastEthernet (IP MTU 1500)the IOS calculates the IP MTU on the tunnel as: 1500-bytes from Ethernet -
24-bytes for the GRE encapsulation = 1476-Bytes1.

質問 # 54
Which two statements about redundant trunk groups on EX Series switches are correct? (Choose two.)

A. Layer 2 control traffic is permitted on the secondary link.
B. Redundant trunk groups use spanning tree to provide loop-free redundant uplinks.
C. If the active link fails, then the secondary link automatically takes over.
D. Redundant trunk groups load balance traffic across two designated uplink interfaces.

正解：A、C

解説：
C is correct because Layer 2 control traffic is permitted on the secondary link of a redundant trunk group (RTG) on EX Series switches. Layer 2 control traffic includes protocols such as LLDP, LACP, and STP, which are used to exchange information and coordinate actions between switches1. According to the Juniper Networks documentation2, Layer 2 control traffic is allowed to pass through both the active and the secondary links of an RTG, but data traffic is only forwarded through the active link. This allows the switches to maintain their Layer 2 adjacencies and monitor the link status on both links.
D is correct because if the active link fails, then the secondary link automatically takes over in an RTG on EX Series switches. An RTG consists of two trunk links: an active or primary link, and a secondary or backup link2. The active link is used to forward data traffic, while the secondary link is in standby mode. If the active link fails or becomes unavailable, the secondary link immediately transitions to a forwarding state and takes over the data traffic without waiting for normal STP convergence2. This provides fast recovery and redundancy for the network.

質問 # 55
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JPNTest JN0-351試験練習テスト問題：https://www.jpntest.com/shiken/JN0-351-mondaishu

JN0-351試験問題解答：https://drive.google.com/open?id=1Gr3B7N6HfuE9y75Q_Oxw09UKH0P6hZb4