Juniper Enterprise Routing and Switching Professional (JNCIP-ENT) JN0-649 Exam Dumps: Updated Questions & Answers (October 2025)

Understanding the Configuration:

The provided configuration and output snippets show how traffic is classified and assigned to different forwarding classes based on the IP precedence values.

The inet-precedence classifier maps specific IP precedence values to forwarding classes with associated loss priorities.

Review of Classifiers:

IP Precedence Value 100:

The IP precedence value 100 in binary is represented as 100 (binary for 4).

Matching with Classifiers:

According to the configuration shown in the exhibit:

classifiers {

inet-precedence cos;

}

The classifier cos maps the following:

forwarding-class expedited-forwarding;

loss-priority low code-points 100;

Conclusion:

The IP precedence value 100 matches the expedited-forwarding forwarding class with low loss-priority as per the configuration.

When video packets are being dropped, and the network is configured to use the expedited-forwarding forwarding class, it typically indicates that the scheduler assigned to this class does not have sufficient bandwidth to handle the traffic. Adjusting the scheduler to allocate more bandwidth to the expedited-forwarding class will ensure that video packets are transmitted without being dropped.

Steps:

Identify the scheduler map: First, identify the scheduler map that is applied to the interfaces. This can be done using the following command:

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show configuration class-of-service scheduler-maps

Adjust the scheduler: Modify the scheduler for the expedited-forwarding forwarding class to support a higher transmit rate. You can edit the scheduler configuration to increase the bandwidth allocated.

Example:

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set class-of-service schedulers expedited-forwarding transmit-rate percent 30

Apply the configuration: Apply the modified scheduler to the interfaces using the following commands:

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set class-of-service interfaces ge-0/0/0 scheduler-map

set class-of-service interfaces ge-0/0/1 scheduler-map

commit

References:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

802.1X Authentication and Re-authentication:

802.1X is used for network access control, where clients (supplicants) authenticate through a RADIUS server.

If a client cannot re-authenticate, the network access behavior depends on the configured action.

Permit Access Configuration:

The permit action ensures that the client continues to have network access if re-authentication fails.

This is crucial in scenarios where continuous access is needed despite temporary authentication issues.

Configuration Syntax:

On the Juniper device, configure the permit action:

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set protocols dot1x authenticator authentication-profile re-authentication permit

References:

Juniper documentation on 802.1X configuration

Understanding 802.1X re-authentication and access control mechanisms

Step 1: Identify the problem.

Devices do not support VPN NLRI, and you must prevent these devices from receiving BGP VPN routes.

Step 2: Analyze the possible solutions.

Option A: Configure an import policy on the remote peer to reject the routes when they are received.

This approach would require configuration on the remote peer, which might not always be practical or possible.

Option B: Configure an export policy on the local BGP peer to reject the VPN routes being sent to the remote peer.

This ensures the local BGP peer does not send the VPN routes to the remote peer, directly addressing the problem.

Option C: Configure a route reflector for the VPN NLRI.

This does not solve the issue of preventing the advertisement of VPN routes to non-supporting peers.

Option D: Configure the apply-vpn-export feature on the local BGP peer.

This feature ensures that the VPN export policies are applied, preventing the advertisement of VPN routes to peers that do not support VPN NLRI.

Step 3: Verify the configurations.

Option B and Option D directly address the requirement without needing configurations on the remote peer.

References:

Juniper BGP configuration guide on export policies​​​​​​.

Commands for applying export policies:

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set policy-options policy-statement term from protocol bgp-vpn

set policy-options policy-statement term then reject

set protocols bgp group export

set protocols bgp apply-vpn-export

To ensure proper functioning within an MST (Multiple Spanning Tree) region, the following parameters must match across all switches:

Revision number:

The revision number identifies the version of the MST configuration. All switches within the same MST region must have the same revision number to ensure consistency.

MSTI-to-VLAN mapping:

The MSTI (Multiple Spanning Tree Instance) to VLAN mapping must be identical on all switches. This mapping ensures that each VLAN is assigned to the correct spanning tree instance.

Configuration name:

The configuration name (or region name) must be the same across all switches. This name uniquely identifies the MST region and must be consistent to ensure switches recognize they are part of the same region.

References:

The MSTP configuration requirements are detailed in Juniper network configuration guides and standards documents on MSTP​​​​.

To troubleshoot why ISP peers are not receiving any routes in a multihomed BGP setup, the following steps are essential:

Verify Active BGP Routes: Ensure that the BGP routes are active in the routing table. Only active routes can be advertised to BGP peers.

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show route protocol bgp

Verify Export Policies: Check the export policies configured on your router. The export policies determine which routes are advertised to BGP peers. If these policies are incorrectly configured or missing, routes will not be advertised.

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show configuration policy-options policy-statement

show configuration protocols bgp group export

References:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

Dynamic VLAN assignment using 802.1X authentication relies on vendor-specific attributes (VSAs) to assign VLANs dynamically based on the authentication results. The modes that support using VSAs for dynamic VLAN assignment are:

Single-Secure Supplicant Mode: This mode supports a single secure client on a port and can use VSAs to dynamically assign VLANs based on the authentication result.

Multiple Supplicant Mode: This mode supports multiple clients on a single port, each with its own authentication session, and can use VSAs to dynamically assign VLANs.

References:

The Juniper documentation and configuration guides discuss the capabilities of these modes in supporting dynamic VLAN assignment through VSAs. Specific configuration examples and guidelines can be found in the documents:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

# Example of enabling single-secure supplicant mode

set protocols dot1x authenticator interface ge-0/0/1.0 supplicant multiple

# Example of enabling multiple supplicant mode

set protocols dot1x authenticator interface ge-0/0/1.0 supplicant multiple