Juniper JN0-351 Enterprise Routing and Switching, Specialist Exam Practice Test

Page: 1 / 14
Total 65 questions
Question 1

You are an operator for a network running 1S-IS. Two routers are failing to form an adjacency. What are two reasons for this problem? (Choose two.)



Answer : B, D

The two reasons for the failure to form an adjacency in a network running IS-IS could be:

B) There is no configured ISO address on any IS-IS interface.IS-IS requires each router interface to have an ISO address configured.Without this address, the routers cannot form an adjacency1.

D) The family iso configuration is missing from the adjacency interface.The 'family iso' configuration is essential for IS-IS to function correctly.If this configuration is missing from the adjacency interface, it could prevent the formation of an adjacency1.

These explanations are based on the Enterprise Routing and Switching Specialist (JNCIS-ENT) documents and learning resources available at Juniper Networks23.


Question 2

Exhibit

You are receiving the BGP route shown in the exhibit from four different upstream ISPs.

Referring to the exhibit, which ISP will be selected as the active path?



Answer : C

In BGP, the path selection process is based on a set of attributes1.The process starts by preferring the path with the highest weight, then the highest local preference, then the locally originated routes, and so on1.If all these attributes are the same, then it prefers the path with the shortest AS path1.

Referring to the exhibit, all four ISPs have the same weight, local preference, and origin1.However, ISP 4 has the shortest AS path1. Therefore, ISP 4 will be selected as the active path. So, option C is correct.


Question 3

Which two statements correctly describe RSTP port roles? (Choose two.)



Answer : A, D

In Rapid Spanning Tree Protocol (RSTP), there are several port roles that determine the behavior of the port in the spanning tree1.

Option A suggests that the designated port forwards data to the downstream network segment or device.This is correct because the designated port is the port on a network segment that has the best path to the root bridge1.It's responsible for forwarding frames towards the root bridge and sending configuration messages into its segment1.

Option D suggests that the root port is responsible for forwarding data to the root bridge.This is also correct because the root port is always the link directly connected to the root bridge, or the shortest path to the root bridge1.It's used to forward traffic towards the root bridge1.

Therefore, options A and D are correct.


Question 4

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?



Answer : B

The exhibit shows the configuration of RSTP on EX-4, which has the commandforce-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 thedelete protocols rstp force-versioncommand in configuration mode1.


Question 5

You have two OSPF routers forming an adjacency. R1 has a priority of 32 and a router ID of 192.168.1.2. R2 has a priority of 64 and a router ID of 192.168.1.1. The routers were started at the same time and all other OSPF settings are the default settings.

Which statement is correct in this scenario?



Answer : D

In OSPF, the Designated Router (DR) and Backup Designated Router (BDR) are elected based on the priority of the routers1.The router with the highest priority becomes the DR, and the router with the second highest priority becomes the BDR1.If there is a tie in priority, then the router with the highest Router ID is chosen1.

In this scenario, R2 has a higher priority (64) than R1 (32), so R2 will become the DR1.Since R1 has the second highest priority, it will become the BDR1. Therefore, option D is correct.


Question 6

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



Answer : B, C

Bis 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.

Cis 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.


Question 7

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



Answer : A, D

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.


Page:    1 / 14   
Total 65 questions