Juniper JN0-637 JNCIP-SEC Exam Practice Test Instant Access

Question 1

Click the Exhibit button.

Referring to the exhibit, which two statements are correct? (Choose two.)

AThis device is the backup node for SRG1.

BThe ge-0/0/3.0 and ge-0/0/4.0 interfaces are not active and will not respond to ARP requests to the virtual IP MAC address.

CThis device is the active node for SRG1.

DThe ge-0/0/3.0 and ge-0/0/4.0 interfaces are active and will respond to ARP requests to the virtual IP MAC address.

Answer : C, D

Question 2

Click the Exhibit button.

Referring to the exhibit, which two statements are correct? (Choose two.)

AYou cannot secure intra-VLAN traffic with a security policy on this device.

BYou can secure inter-VLAN traffic with a security policy on this device.

CThe device can pass Layer 2 and Layer 3 traffic at the same time.

DThe device cannot pass Layer 2 and Layer 3 traffic at the same time.

Answer : A, D

Comprehensive Detailed Step-by-Step Explanation with All Juniper Security Reference

Understanding the Exhibit:

The SRX device is operating in Transparent Mode, as indicated by:

Global Mode : Transparent bridge

Transparent Mode on SRX Devices:

Transparent Mode (Layer 2 Mode):

The SRX device acts as a Layer 2 switch.

Does not perform routing functions.

Security policies can be applied to inter-VLAN (Layer 2) traffic but not intra-VLAN traffic.

Cannot handle Layer 3 traffic simultaneously.

Option A: You cannot secure intra-VLAN traffic with a security policy on this device.

True.

In Transparent Mode, intra-VLAN traffic is switched within the VLAN and does not pass through the SRX firewall processing engine.

Therefore, security policies cannot be applied to intra-VLAN traffic.

Option B: You can secure inter-VLAN traffic with a security policy on this device.

False.

In Transparent Mode, all interfaces are in the same VLAN (unless VLAN tagging is configured).

Inter-VLAN routing is not possible as the device does not perform Layer 3 functions.

Option C: The device can pass Layer 2 and Layer 3 traffic at the same time.

False.

In Transparent Mode, the SRX device operates exclusively at Layer 2.

It cannot process Layer 3 traffic simultaneously.

Option D: The device cannot pass Layer 2 and Layer 3 traffic at the same time.

True.

The SRX device in Transparent Mode cannot handle both Layer 2 and Layer 3 traffic concurrently.

Key Points:

Intra-VLAN Traffic:

Traffic within the same VLAN.

In Transparent Mode, this traffic is switched and does not go through the firewall's security policies.

Inter-VLAN Traffic:

Traffic between different VLANs.

Requires routing capabilities (Layer 3).

In Transparent Mode, the SRX cannot perform routing functions.

Juniper Security Reference:

Juniper Networks Documentation:

'In transparent mode, the SRX Series device acts like a Layer 2 switch or bridge. Security policies cannot control intra-VLAN traffic because such traffic does not pass through the firewall.'

Source: Understanding Transparent Mode

'The device cannot perform both Layer 2 switching and Layer 3 routing simultaneously in transparent mode.'

Source: Transparent Mode Limitations

Conclusion:

Option A is correct because intra-VLAN traffic cannot be secured with security policies in Transparent Mode.

Option D is correct because the device cannot pass both Layer 2 and Layer 3 traffic at the same time when operating in Transparent Mode.

Question 3

Referring to the exhibit,

which two statements are correct about the NAT configuration? (Choose two.)

ABoth the internal and the external host can initiate a session after the initial translation.

BOnly a specific host can initiate a session to the reflexive address after the initial session.

CAny external host will be able to initiate a session to the reflexive address.

DThe original destination port is used for the source port for the session.

Answer : A, B

Question 4

A company has acquired a new branch office that has the same address space of one of its local networks, 192.168.100/24. The offices need to communicate with each other.

Which two NAT configurations will satisfy this requirement? (Choose two.)

A[edit security nat source]
user@OfficeA# show rule-set OfficeBtoA {
from zone OfficeB;
to zone OfficeA;
rule 1 {
match {
source-address 192.168.210.0/24;
destination-address 192.168.200.0/24;
}
then {
source-nat {
interface;
}
}
}
}

B[edit security nat static]
user@OfficeA# show rule-set From-Office-B {
from interface ge-0/0/0.0;
rule 1 {
match {
destination-address 192.168.200.0/24;
}
then {
static-nat {
prefix 192.168.100.0/24;
}
}
}
}

C[edit security nat static]
user@OfficeB# show rule-set From-Office-A {
from interface ge-0/0/0.0;
rule 1 {
match {
destination-address 192.168.210.0/24;
}
then {
static-nat {
prefix 192.168.100.0/24;
}
}
}
}

D[edit security nat source]
user@OfficeB# show rule-set OfficeAtoB {
from zone OfficeA;
to zone OfficeB;
rule 1 {
match {
source-address 192.168.200.0/24;
destination-address 192.168.210.0/24;
}
then {
source-nat {
interface;
}
}
}
}

Answer : A, D

The problem describes two offices needing to communicate, but both share the same IP address space, 192.168.100.0/24. To resolve this, NAT must be configured to translate the conflicting address spaces on each side. Here's how each of the configurations works:

Option A (Correct):

This source NAT rule translates the source address of traffic from Office B to Office A. By configuring source NAT, the source IP addresses from Office B (192.168.210.0/24) will be translated when communicating with Office A (192.168.200.0/24). This method ensures that there is no overlap in address space when packets are transmitted between the two offices.

Option D (Correct):

This is a source NAT rule configured on Office B, which translates the source addresses from Office A to prevent address conflicts. It ensures that when traffic is initiated from Office A to Office B, the overlapping address range (192.168.100.0/24) is translated.

Options B and C (Incorrect):

These options involve static NAT rules that map address ranges between the two offices, but they do not resolve the overlapping IP address space issue effectively. Static NAT is not the optimal solution in this scenario since the problem involves address space conflict, which requires translation of source addresses during communication.

Juniper Reference:

Juniper NAT Configuration Guide: Detailed instructions on how to configure source NAT and resolve address conflicts between networks.

Question 5

In a multinode HA environment, which service must be configured to synchronize between nodes?

AAdvanced policy-based routing

BPKI certificates

CIPsec VPN

DIDP

Answer : B

Question 6

You need to set up source NAT so that external hosts can initiate connections to an internal device, but only if a connection to the device was first initiated by the internal device.

Which type of NAT solution provides this functionality?

AAddress persistence

BPersistent NAT with any remote host

CPersistent NAT with target host

DStatic NAT

Answer : C

Persistent NAT with target host allows external hosts to establish connections only when the internal device initiates a session first, ideal for specific interactive applications. Refer to Juniper Persistent NAT Documentation.

The scenario requires that external hosts be able to initiate a connection only if the internal device has already initiated a connection. The correct solution is Persistent NAT with target host, which ensures that a specific external host can initiate new connections back to the internal device, but only after the internal device has established a session first.

Persistent NAT with Target Host (Answer C): This allows the internal device to initiate a connection, and once established, the specified external host can also initiate new connections to the internal device on the same NAT mapping.

Example Configuration:

bash

set security nat source persistent-nat permit target-host-port

This solution is appropriate when controlled bidirectional communication is required based on an internal-initiated connection.

Question 7

You are deploying a large-scale VPN spanning six sites. You need to choose a VPN technology that satisfies the following requirements:

All sites must have secure reachability to all other sites.

New spoke sites can be added without explicit configuration on the hub site.

All spoke-to-spoke communication must traverse the hub site.

Which VPN technology will satisfy these requirements?

AADVPN

BGroup VPN

CSecure Connect VPN

DAutoVPN

Answer : D

AutoVPN simplifies deployment by dynamically establishing tunnels from spokes to the hub. This architecture supports easy scaling with minimal configuration changes, ensuring spoke-to-spoke traffic flows through the hub. For more information, see Juniper AutoVPN Overview.

In this scenario, you need a VPN solution that ensures secure, dynamic connectivity between multiple sites, with the following conditions:

All sites must have secure reachability.

New spoke sites can be added without explicit configuration on the hub site.

Spoke-to-spoke communication must traverse the hub.

The correct technology to meet these requirements is AutoVPN. It simplifies VPN configurations by automating the setup between hub and spoke sites. Additionally, AutoVPN automatically establishes secure tunnels for new spoke sites without requiring manual configuration at the hub, and all spoke-to-spoke traffic is routed through the hub.

Juniper JN0-637 Security, Professional JNCIP-SEC Exam Practice Test