JN0-1103 Design - Associate (JNCIA-Design) Questions and Answers

IPsec with NAT Traversal (NAT-T) encapsulates IPsec packets within UDP headers, adding additional overhead compared to standard IPsec. This results in higher packet overhead, which can affect performance and MTU handling more than other VPN protocols.

For a cost-sensitive small data center, the EX4300 and EX4400 switches are suitable leaf node options. They offer sufficient port density and features like Virtual Chassis or EVPN-VXLAN (EX4400) at a lower cost compared to high-end QFX models.

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.

In SD-WAN,path selections are made at the local routing engine level on each SD-WAN router based on policies defined by the centralized controller. This allows for real-time, dynamic traffic steering without requiring per-packet decisions from the controller.

Using a Virtual Chassis (VC) introduces a single point of failure in the management plane, as all member switches depend on a master for control. Replacing the VC with ESI-LAG (Ethernet Segment Identifier - Link Aggregation Group) allows dual-homed servers to connect to independent leaf switches while maintaining resiliency and independent management planes—thus eliminating the single point of failure.

The diagram shows an enterprise WAN connected to two different ISPs through edge routers, with security elements in place. This configuration is characteristic of an Internet edge design, where the enterprise network interfaces with external service providers, providing redundancy and secure access to the internet.

A Secure Web Gateway (SWG) provides proxy services to inspect and filter web traffic and includes firewall capabilities to enforce security policies, block threats, and control access to internet resources.

For reliable out-of-band management and recovery from misconfigurations, terminal servers should be connected through a separate network, such as a 4G LTE modem or a parallel network of independent routers. This ensures access remains available even if the production network is down.

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.

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.

Encrypted Traffic Insights is a Juniper ATP Cloud feature that detects threats within HTTPS trafficwithout decrypting it. It uses metadata, machine learning, and behavioral analysis to identify anomalies while maintaining privacy.

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.

PTX Series routers are purpose-built for the core network, offering ultra-high throughput, scalability, and low-latency forwarding ideal for service provider and large-scale data center cores.

In a 3-stage IP fabric, each leaf node must connect to every spine node to ensure full mesh connectivity at Layer 3 between leafs via the spine layer. This design supports ECMP and optimal traffic distribution across the fabric.

Juniper’s SASE (Secure Access Service Edge) solution combines Juniper Secure Edge, which delivers cloud-based security services, and Mist AI-Driven SD-WAN, which provides secure, intelligent WAN connectivity. Together, they support secure, seamless access across distributed environments.