JN0-682 Practice Exam Questions with Answers Data Center Professional (JNCIP-DC) Certification

In an EVPN environment, VRF (Virtual Routing and Forwarding) import policies along with community values can be used to selectively accept certain MAC advertisement routes. These policies can be configured to include or exclude specific routes based on community values, allowing for granular control over the routes accepted from EVPN peers.

References:

• Juniper Networks - EVPN for VXLAN Configuration Guide

An SRX Chassis cluster setup is ideal for implementing perimeter security with Layer 7 inspection and ensuring no interruption in traffic flow even if a port or device fails. The chassis cluster configuration provides redundancy and high availability for critical security functions.

References:

• Juniper Networks - SRX Series Services Gateways

A. EVPN signaling reduces ARP flooding, while multicast signaling does not. EVPN uses BGP to distribute MAC address information, which can also include IP address bindings, thereby eliminating the need for ARP flooding across the VXLAN overlay. B. EVPN signaling propagates MAC addresses across the network, while multicast signaling does not. In an EVPN environment, MAC address advertisements are distributed via BGP EVPN routes, enabling efficient and scalable MAC address learning and distribution.

References:

• EVPN Overview

Configuring Proxy ARP on leaf devices in an EVPN overlay network enables them to respond to ARP requests on behalf of other hosts. When the leaf device knows the MAC of the intended destination, it can reply to ARP requests with its own MAC address, thus facilitating local resolution and avoiding unnecessary ARP traffic across the overlay.

The endpoint of a VXLAN tunnel is known as a VTEP (VXLAN Tunnel Endpoint). VTEPs are responsible for encapsulating and de-encapsulating the traffic sent over the VXLAN network.

References:

• Juniper Networks - VXLAN Overview

https://www.juniper.net/documentation/us/en/software/junos/ovsdb-vxlan-qfx/topics/example/overlay-ping-traceroute-vxlan.html

VRF (Virtual Routing and Forwarding) instances can be used in conjunction with Layer 3 logical interfaces. Each logical Layer 3 interface can belong to only one VRF, maintaining separation and isolation of routing tables, which is essential for multitenancy and network segmentation.References:

• VRF Lite Configuration

The Junos Telemetry Interface (JTI) is the ideal solution for monitoring and telemetry in an IP fabric using QFX Series devices. JTI uses a push model to stream system event data and statistical data from the devices. It provides real-time, granular monitoring capabilities, which is more efficient and scalable compared to

traditional polling methods like SNMP. By pushing data to a telemetry server, JTI allows for more dynamic and immediate insights into network performance and health.References:Juniper Networks QFX Series Documentation - Junos Telemetry Interface.

In a scenario where RSVP and LDP are restricted, and routes are not appearing in the inet table, the use of "bgp family inet labeled-unicast per-group-label" becomes necessary. This setting is crucial in environments where label distribution protocols like RSVP or LDP are not used. It enables the use of MPLS labels in BGP without relying on these protocols, which is essential for integrating L3VPN with EVPN over WAN links that do not support RSVP or LDP. The “per-group-label” option ensures that a single label is used for all routes exchanged with a BGP neighbor, which simplifies label management and conserves label space.References:

• Junos OS Routing Protocols Library for Routing Devices

In a spine and leaf-based IP fabric, when a device or link fails, the traffic is rerouted within the fabric (A), ensuring high availability and resiliency. This architecture is designed to dynamically adapt to changes and reroute traffic as needed. Furthermore, Clos networks, which are the basis for spine-leaf architectures, demonstrate good scaling features (D) as they allow for easy expansion of the network by adding more spine or leaf switches without significant changes to the existing infrastructure.References:

• Juniper Networks - Spine-and-Leaf Architectures
• Understanding Spine-and-Leaf Network Topologies

BGP Additional Paths in EVPN-VXLAN environments enable the advertisement of multiple paths through BGP, which provides faster network convergence in the event of a leaf node link failure. This is especially important in large-scale networks with thousands of MAC addresses.

B. Virtual Router Redundancy Protocol (VRRP) ensures high availability by allowing multiple routers to work together to provide network resilience.

C. Graceful Routing Engine switchover (GRES) allows for the seamless transition of control plane functions between Routing Engines, ensuring continuous operation of the network.

D. Dual Routing Engines provide a hardware-based high-availability solution, where a backup Routing Engine takes over in case the primary fails, ensuring uninterrupted network service.

In Zero Touch Provisioning (ZTP), the process is streamlined to simplify the deployment of new switches in the network. When a switch that supports ZTP boots and does not find a configuration file, it attempts to acquire one using DHCP. If the switch is already running the firmware image specified by the DHCP server (if mentioned), it proceeds to the next step without re-downloading the image. DHCP Option 43 suboption 01 is used by the DHCP server to provide the URL of the configuration file to the switch.

References

• Zero Touch Provisioning

In an EBGP-based IP fabric architecture, the spine nodes form peering relationships with both other spine nodes and leaf nodes. However, the leaf nodes are configured to only form peering relationships with the spine nodes, not with other leaf nodes. This hierarchical approach simplifies the network topology and routing.

References:

• Juniper Networks - IP Fabric Architecture Guide

In a data center IP fabric scenario, Multi-Protocol Border Gateway Protocol (MP-BGP) is used to support Ethernet VPN (EVPN). EVPN is a next-generation solution for multipoint L2VPN services that combines both Layer 2 and Layer 3 attributes. MP-BGP is essential for EVPN as it provides the control plane for EVPN by advertising MAC addresses, IP address information, and VXLAN information.References:Juniper Networks Documentation, EVPN Overview.

In a DCI (Data Center Interconnect) scenario where IP subnets between data centers are completely unique, Type 5 EVPN routes (IP Prefix routes) are used. These routes allow for the advertisement of IP prefixes over the EVPN, facilitating inter-data center communication without IP overlap issues.

MACsec (Media Access Control Security) is the technology used to secure ARP and DHCP traffic across local Ethernet links. It provides secure, encrypted communication at the MAC layer, ensuring that traffic like ARP and DHCP is protected from eavesdropping and tampering.

References:

• Juniper Networks - MACsec Overview

To accommodate the extra header information added by VXLAN, which can be 50 to 54 bytes, it's necessary to increase the MTU (Maximum Transmission Unit) on the physical interfaces connected to the VXLAN network. This ensures that the larger frames can be transmitted without fragmentation, maintaining efficient network performance.

For a Data Center Interconnect (DCI) over an IP network, Layer 2 data needs to be encapsulated. This encapsulation, typically using VXLAN or similar technologies, allows Layer 2 traffic to traverse an IP network while preserving the Layer 2 information.

References:

• Juniper Networks - Data Center Interconnect Solutions

A. Allowing Junos to dynamically create the virtual MAC address of the IRB interface ensures unique MAC addresses for redundancy and avoids conflicts. C. Configuring both IRB interfaces manually with the same address ensures consistency and helps in creating a redundant Layer 3 gateway setup.

For enabling visibility into EVPN-VXLAN network traffic through continuous monitoring:

• You must enable sFlow monitoring on each interface individually (Option C):sFlow is a sampling technology used for monitoring network traffic. In a Juniper environment, sFlow needs to be enabled on individual interfaces to start collecting traffic samples. This allows for granular control over which interfaces are monitored.
• You cannot enable sFlow monitoring on each interface individually (Option A):This statement is incorrect, contradicting the above explanation. sFlow can and should be enabled on specific interfaces as needed.

The option stating that the sFlow agent needs to be manually installed on QFX Series switches (Option D) is inaccurate, as the sFlow feature is typically integrated into the Junos OS running on QFX Series switches. The statement about the sFlow agent being installed by default on QFX Series switches (Option B) is partially true but does not directly address the question of enabling visibility into network traffic.

References

• Juniper Networks: Configuring sFlow Technology for Network Monitoring

To enable communication between VXLANs in different data centers across a WAN connection using an MX Series router, Integrated Routing and Bridging (IRB) interfaces must be configured. IRB interfaces provide Layer 3 routing capabilities within a VXLAN overlay network, allowing for inter-VXLAN routing. By configuring IRB interfaces on the MX router, you enable it to act as a Layer 3 gateway, routing traffic between the different VXLANs across the data centers.References:Juniper Networks MX Series Documentation - VXLAN and EVPN Configuration.

Any to any connectivity is a key advantage of using MPLS for data center interconnects (DCIs). It allows for flexible and efficient connectivity options between various data center locations.

Traffic engineering is another significant advantage. MPLS allows for the control and optimization of traffic flows within the network, providing enhanced performance and efficient use of network resources

The Contrail Command user interface supports various functions including configuring management domains and creating virtual networks. It provides an integrated platform for managing and configuring network resources in a centralized manner.

References:

• Juniper Networks - Contrail Networking Documentation