Free Practice Questions for Juniper JN0-637 Exam

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

Understanding Multinode HA:

Chassis Cluster in Active/Passive Mode:

One node is active, and the other is standby.

Dynamic Routing Protocols:

Run on the active node only.

Option A: Dynamic routing is active on one device at a time.

Explanation:

In active/passive HA, dynamic routing protocols run only on the primary (active) node.

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In the scenario where internal users are trying to access the company's web server via its FQDN but the DNS server resolves to a private IP, two key actions are needed:

Static NAT (Answer B): Since the internal DNS server resolves the web server to its private IP address (10.10.10.4/24), you need to configure static NAT for both the DNS server and the webserver. This will ensure that requests coming from the internet will be translated to the web server's public IP (203.0.113.4) and the DNS server’s public IP (203.0.113.2).

Example Command:

bash

set security nat static rule-set public-to-private from zone untrust

set security nat static rule-set public-to-private rule dns-server match destination-address 203.0.113.2/32

set security nat static rule-set public-to-private rule dns-server then static-nat-prefix 10.10.10.2/32

set security nat static rule-set public-to-private rule web-server match destination-address 203.0.113.4/32

set security nat static rule-set public-to-private rule web-server then static-nat-prefix 10.10.10.4/32

Proxy ARP (Answer D): The SRX needs to respond to ARP requests for the public IP addresses of both the DNS and webserver on the interface facing the internet (ge-0/0/3). This allows the SRX to handle requests directed at the public IPs.

Example Command:

set interfaces ge-0/0/3 unit 0 family inet proxy-arp interface-address 203.0.113.2/32

set interfaces ge-0/0/3 unit 0 family inet proxy-arp interface-address 203.0.113.4/32

These two configurations allow external users to access the internal web server via its public IP, as resolved by the DNS server.

The interfaces are active and respond to ARP for virtual IP as long as the node is the primary or active node in the SRG group. This ensures high availability and proper traffic forwarding. For information, refer to Juniper SRX HA Documentation.

The exhibit shows information about a chassis cluster and its services redundancy group (SRG1). Let's analyze the relevant details:

Explanation of Answer B (Backup Node for SRG1):

The exhibit indicates that this SRX device is in the backup role for SRG1. The status: BACKUP field confirms that this device is currently in a standby role and is not the active node for the services redundancy group.

Explanation of Answer A (Interfaces Not Active):

Since the device is in the backup role, the interfaces ge-0/0/3.0 and ge-0/0/4.0 will not respond to ARP requests for the virtual IP's MAC address. Only the active node's interfaces respond to ARP requests in a chassis cluster configuration.

Juniper Security Reference:

Chassis Cluster Redundancy Overview: In a chassis cluster, the backup node does not respond to ARP requests for the virtual IP. Only the active node handles such requests to ensure seamless traffic forwarding. Reference: Juniper Chassis Cluster Documentation.

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

Understanding the Scenario:

Objective: Deploy OSPF over IPsec between an SRX Series device and a third-party device using GRE tunnels.

Components Involved:

GRE (Generic Routing Encapsulation): Encapsulates packets to allow routing protocols like OSPF to run over IPsec tunnels.

IPsec: Provides security for the GRE tunnels.

OSPF: Dynamic routing protocol used over the GRE tunnel.

Option A: The GRE interface should use lo0 as endpoints.

Explanation:

Using the loopback interface (lo0) as the source and destination endpoints for GRE tunnels is a common best practice.

Advantages:

Stability: Loopback interfaces are always up, ensuring the GRE tunnel remains operational even if physical interfaces fail.

Reachability: Provides consistent endpoint IP addresses for GRE tunnels.

Configuration:

Assign IP addresses to lo0 interfaces on both devices.

Configure GRE tunnels to use these lo0 IP addresses as source and destination.