Juniper JN0-1103 Design - Associate (JNCIA-Design) Exam Practice Test

In a Clos data center fabric using IBGP as the underlay, BGP ADD-PATH must be enabled to allow multiple equal-cost paths to be advertised and installed on the leaf switches. This supports ECMP (Equal-Cost Multi-Path) routing, which is essential for optimal traffic distribution in the fabric.

The highlighted device connects to multiple servers and also connects upstream to spine switches. This placement and function identify it as a leaf node in a leaf-spine architecture, responsible for connecting endpoints (such as servers) into the fabric.

Using discrete border leafs enables design flexibility, such as applying different oversubscription ratios for east-west (intra-fabric) and north-south (external) traffic. This separation improves scalability and performance tuning compared to placing border roles directly on spines.

The oversubscription ratio in an IP fabric is influenced by the number of spine nodes relative to the number of leaf nodes and their uplinks.

Removing spine nodes reduces available uplink bandwidth, increasing oversubscription.

Adding spine nodes increases available bandwidth between leafs and spines, decreasing the oversubscription ratio.

These elements directly impact port density and scaling requirements in a campus switching design. Understanding the number of unmanned devices, fixed user workstations with IP phones, and standalone VoIP phones is critical for calculating the total number of access ports needed and ensuring the infrastructure can support current and future capacity demands.

Capacity planning requires a clear view of the current application behavior to assess real-time demands and predicting future traffic projections to ensure the network can scale efficiently and handle increased load over time.

Reducing the oversubscription ratio means provisioning more uplink bandwidth relative to access bandwidth, which improves congestion handling and performance but also increases network cost due to the need for additional or higher-capacity links and equipment.

For a 120-meter (400-foot) connection between switches, multimode fiber is the most reliable and cost-effective option. It supports higher bandwidth and longer distances than UTP (which is limited to 100 meters) and is more stable and secure than a wireless solution.

The OAMP management methodology stands for Operations, Administration, Maintenance, and Provisioning. These categories define key areas in managing and sustaining network infrastructure effectively.

SD-WANallows branches to aggregate multiple WAN links(e.g., MPLS, broadband, LTE) to optimize performance and redundancy. It also supports local breakoutfor Direct Internet Access (DIA), improving cloud application performance by avoiding backhaul to a central site.

In an ESI-LAG configuration, both VTEPs (leaf switches) advertise reachability to the same Ethernet Segment Identifier, ensuring redundancy and load balancing. To make this work correctly with LACP, thesystem ID must be identical on both leafs so that the downstream device sees them as a single LAG endpoint.

When placing access points on the same channel, the recommended signal strength threshold to minimize co-channel interference is −65 dBm. This ensures adequate coverage while avoiding signal overlap that can degrade wireless performance.

WAN aggregation is represented by the central router that connects multiple branch sites through a Carrier Ethernet service to the enterprise WAN, consolidating traffic.

Private WAN is shown through the use of Carrier Ethernet, which is a private service providing secure, dedicated connectivity between branches and the enterprise WAN.

In Juniper Networks' enterprise network designs, the distribution layer typically uses QFX and EX Series switches. These platforms provide the necessary scalability, performance, and Layer 3 capabilities to aggregate access layer switches and support routing between VLANs.

SD-WAN routes traffic, including security-sensitive data, across MPLS, VPNs, and Internet circuits using encryption and policy-based routing to ensure secure and efficient transmission, even over public networks.

The Juniper Connected Security strategy aims to integrate security across the entire network by extending protection to routers, switches, and every point of connection, ensuring that security is enforced holistically - not just at the perimeter.

A private WAN link offers low latency and inherent security without requiring encryption, making it ideal for transmitting sensitive data while conserving computing resources. It ensures dedicated, reliable connectivity between sites.