Juniper JN0-683 Online Practice Questions and Exam Preparation

Juniper JN0-683 Online Questions & Answers

• Question 31:

  As part of the onboarding process for new switches being added to your data centers, your company uses Juniper Networks' ZTP process. As part of the ZTP process, a script is executed by the devices being onboarded.

  Which statement is correct in this scenario?

  A. The Junos ZTP process supports Shell. JScript. and Ansible.
  B. The Junos ZTP process supports Python, SLAX, and Perl.
  C. The Junos ZTP process supports JScript. Ansible. and Perl.
  D. The Junos ZTP process supports Shell. Python, and SLAX.
  D. The Junos ZTP process supports Shell. Python, and SLAX.

  ---

  Explanation

  Zero Touch Provisioning (ZTP):

  Juniper Networks' ZTP (Zero Touch Provisioning) process automates the deployment of new devices by allowing them to fetch and execute scripts for configuration and setup as they are powered on and connected to the network.

  Supported Scripting Languages:

  The Junos OS supports several scripting languages that can be used during the ZTP process:

  Shellscripts are often used for general automation tasks.

  Pythonis a widely supported language in Junos, offering powerful scripting capabilities for automating network tasks.

  SLAX(Service Logic Execution Environment) is a scripting language specific to Junos, designed to automate configuration tasks and simplify network operations.

  Conclusion:

  Option D:Correct--Junos ZTP supports Shell, Python, and SLAX, making it the correct choice among the provided options.

• Question 32:

  Exhibit.

  

  You are troubleshooting a DCI connection to another data center The BGP session to the provider is established, but the session to Border-Leaf-2 is not established. Referring to the exhibit, which configuration change should be made to solve the problem?

  A. set protocols bgp group overlay export loopbacks
  B. delete protocols bgp group UNDERLAY advertise-external
  C. set protocols bgp group PROVIDER export LOOPBACKS
  D. delete protocols bgp group OVERLAY accept-remote-nexthop
  D. delete protocols bgp group OVERLAY accept-remote-nexthop

  ---

  Explanation

  Understanding the Configuration:

  The exhibit shows a BGP configuration on a Border-Leaf device. The BGP group UNDERLAY is used for the underlay network, OVERLAY for EVPN signaling, and PROVIDER for connecting to the provider network.

  The OVERLAY group has the accept-remote-nexthop statement, which is designed to accept the next-hop address learned from the remote peer as is, without modifying it.

  Problem Identification:

  The BGP session to Border-Leaf-2 is not established. A common issue in EVPN-VXLAN environments is related to next-hop reachability, especially when accept-remote-nexthop is configured.

  In typical EVPN-VXLAN setups, the next-hop address should be reachable within the overlay network. However, the accept-remote-nexthop can cause issues if the next-hop IP address is not directly reachable or conflicts with the expected

  behavior in the overlay.

  Corrective Action:

  D. delete protocols bgp group OVERLAY accept-remote-nexthop:Removing this command will ensure that the device uses its own IP address as the next-hop in BGP advertisements, which is standard practice in many EVPN-VXLAN setups.

  This change should help establish the BGP session with Border-Leaf-2. Data Center

  References:

  Proper handling of BGP next-hop attributes is critical in establishing and maintaining stable BGP sessions, especially in complex multi-fabric environments like EVPN-VXLAN. Removing accept- remote-nexthop aligns with best practices in

  many scenarios.

• Question 33:

  You are preparing an sFlow monitoring system configuration.

  In this scenario, what Information will be included in the datagram sent to the sFlow collector? (Choose two.)

  A. the interlace through which the packets entered the agent
  B. the sending device's serial number
  C. the CRC from the sampled packet
  D. the source and destination VLAN for sampled packets
  A. the interlace through which the packets entered the agent
  D. the source and destination VLAN for sampled packets

  ---

  Explanation

  Understanding sFlow Monitoring:

  sFlow is a packet sampling technology used to monitor traffic in a network. It sends sampled packet data and interface counters to an sFlow collector, which analyzes the traffic patterns.

  Information Included in sFlow Datagram:

  Option A:The datagram sent to the sFlow collector includes information about the interface through which the packets entered the agent (the switch or router). This is crucial for understanding where in the network the traffic was captured.

  Option D:sFlow datagrams also include the source and destination VLAN for the sampled packets. This allows for detailed analysis of the traffic flow within different VLANs.

  Conclusion:

  Option A:Correct--The ingress interface is included in the sFlow datagram.

  Option D:Correct--The source and destination VLANs are also included, providing context for the sampled traffic.

• Question 34:

  You are deploying an EVPN-VXLAN overlay. You must ensure that Layer 3 routing happens on the spine devices. In this scenario, which deployment architecture should you use?

  A. ERB
  B. CRB
  C. bridged overlay
  D. distributed symmetric routing
  B. CRB

  ---

  Explanation

  Understanding EVPN-VXLAN Architectures:

  EVPN-VXLAN overlays allow for scalable Layer 2 and Layer 3 services in modern data centers.

  CRB (Centralized Routing and Bridging):In this architecture, the Layer 3 routing is centralized on spine devices, while the leaf devices focus on Layer 2 switching and VXLAN tunneling. This setup is optimal when the goal is to centralize

  routing for ease of management and to avoid complex routing at the leaf level.

  ERB (Edge Routing and Bridging):This architecture places routing functions on the leaf devices, making it a distributed model where each leaf handles routing for its connected hosts.

  Architecture Choice for Spine Routing:

  Given the requirement to ensure Layer 3 routing happens on the spine devices, theCRB (Centralized Routing and Bridging) architecture is the correct choice. This configuration offloads routing tasks to the spine, centralizing control and

  potentially simplifying the overall design.

  With CRB, the spine devices perform all routing between VXLAN segments. Leaf switches handle local switching and VXLAN encapsulation, but routing decisions are centralized at the spine level.

  This model is particularly advantageous in scenarios where centralized management and routing control are desired, reducing the complexity and configuration burden on the leaf switches.

  Data Center

  References:

  The CRB architecture is commonly used in data centers where centralized control and simplified management are key design considerations. It allows the spines to act as the primary routing engines, ensuring that routing is handled in a

  consistent and scalable manner across the fabric.

• Question 35:

  You are selling up an EVPN-VXLAN architecture (or your new data center. thisinitial deployment will be less than 50 switches: however, it could scale up to 250 switches over time supporting 1024 VLANs. You are still deciding whether to use symmetric or asymmetric routing.

  In this scenario, which two statements are correct? (Choose two.)

  A. Symmetric routing needs an extra VLAN with an IRB interface for each L3 VRF instance.
  B. Asymmetric routing is easier lo monitor because of the transit VNI.
  C. Symmetric routing supports higher scaling numbers.
  D. Asymmetric routing routes traffic on the egress switch.
  C. Symmetric routing supports higher scaling numbers.
  D. Asymmetric routing routes traffic on the egress switch.

  ---

  Explanation

  Symmetric vs. Asymmetric Routing in EVPN-VXLAN:

  Symmetric Routing:Traffic enters and exits the VXLAN network through the same VTEP, regardless of the source or destination. This approach simplifies routing decisions, especially in large networks, and is generally more scalable.

  Asymmetric Routing:The routing occurs on the egress VTEP. This method can be simpler to deploy in smaller environments but becomes complex as the network scales, particularly with larger numbers of VNIs and VLANs.

  Correct Statements:

  C. Symmetric routing supports higher scaling numbers:Symmetric routing is preferred in larger EVPN-VXLAN deployments because it centralizes routing decisions, which can be more easily managed and scaled.

  D. Asymmetric routing routes traffic on the egress switch:This is accurate, as asymmetric routing means the routing decision is made at the final hop, i.e., the egress VTEP before the traffic reaches its destination.

  Incorrect Statements:

  A. Symmetric routing needs an extra VLAN with an IRB interface for each L3 VRF instance:This is not accurate. Symmetric routing does not require an extra VLAN per VRF; rather, it uses the same VLAN/VNI across the network, simplifying

  routing and VLAN management.

  B. Asymmetric routing is easier to monitor because of the transit VNI:Asymmetric routing is not necessarily easier to monitor; in fact, it can add complexity due to the split routing logic between ingress and egress points.

  Data Center

  References:

  The choice between symmetric and asymmetric routing in an EVPN-VXLAN environment depends on network size, complexity, and specific operational requirements. Symmetric routing is generally more scalable and easier to manage in

  large-scale deployments.

• Question 36:

  Which two statements are true about IP fabrics using unnumbered BGP? (Choose two.)

  A. Unnumbered BGP requires that family inet6is configured on each interface.
  B. Unnumbered BGP peering automatically provisions IPv6 peering.
  C. Unnumbered BGP requires that family inet is configured on each interface.
  D. Unnumbered BGP peering automatically provisions IPv4 peering.
  C. Unnumbered BGP requires that family inet is configured on each interface.
  D. Unnumbered BGP peering automatically provisions IPv4 peering.

  ---

  Explanation

  Understanding Unnumbered BGP:

  Unnumbered BGP (Border Gateway Protocol) allows BGP peering between routers without assigning specific IP addresses to the interfaces. Instead, it uses the loopback address or another router identifier for the BGP session, making IP

  address management more straightforward in large-scale networks.

  Family inet Configuration:

  Option C:The family inet configuration is required on each interface involved in unnumbered BGP peering to support IPv4 address families. This ensures that IPv4 peering sessions can be established between devices.

  Automatic IPv4 Peering:

  Option D:Unnumbered BGP peering automatically provisions IPv4 peering sessions. This simplifies the configuration by eliminating the need to manually assign and manage IP addresses for BGP peering.

  Conclusion:

  Option C:Correct--Unnumbered BGP requires the family inet configuration for IPv4. Option D:Correct--Unnumbered BGP automatically provisions IPv4 peering, simplifying setup.

• Question 37:

  Exhibit.

  

  A VXLAN tunnel has been created between leaf1and Ieaf2 in your data center. Referring to the exhibit, which statement is correct?

  A. Traffic sent from server1to server2 will be dropped on Ieaf2.
  B. Traffic sent from server1to server2 will be tagged with VLAN ID 100 on Ieaf2 and forwarded to server2.
  C. Traffic sent from server1to server2 will be tagged with VLAN ID 200 on Ieaf2 and forwarded to server2.
  D. Traffic sent from server1to server2 will be dropped on leaf1.
  C. Traffic sent from server1to server2 will be tagged with VLAN ID 200 on Ieaf2 and forwarded to server2.

  ---

  Explanation

  Understanding VXLAN Tunneling:

  VXLAN (Virtual Extensible LAN) is a network virtualization technology that addresses the scalability issues associated with traditional VLANs. VXLAN encapsulates Ethernet frames in UDP, allowing Layer 2 connectivity to extend across Layer

  3 networks.

  Each VXLAN network is identified by a unique VXLAN Network Identifier (VNI). In this exhibit, we have two VNIs, 5100 and 5200, assigned to the VXLAN tunnels between leaf1 and leaf2. Network Setup Details:

  Leaf1:Connected to Server1 with VLAN ID 100 and associated with VNI 5100.

  Leaf2:Connected to Server2 with VLAN ID 200 and associated with VNI 5200.

  Spine:Acts as the interconnect between leaf switches.

  Traffic Flow Analysis:

  When traffic is sent from Server1 to Server2, it is initially tagged with VLAN ID 100 on leaf1. The traffic is encapsulated into a VXLAN packet with VNI 5100 on leaf1. The packet is then sent across the network (via the spine) to leaf2. On leaf2, the VXLAN header is removed, and the original Ethernet frame is decapsulated.

  Leaf2 will then associate this traffic with VLAN ID 200 before forwarding it to Server2. Correct Interpretation of the Exhibit:

  The traffic originating from Server1, which is tagged with VLAN ID 100, will be encapsulated into VXLAN and transmitted to leaf2. Upon arrival at leaf2, it will be decapsulated, and since it is associated with VNI 5200 on leaf2, the traffic will be retagged with VLAN ID 200.

  Therefore, the traffic will reach Server2 tagged with VLAN ID 200, which matches the network configuration shown in the exhibit.

  Data Center

  References:

  This configuration is typical in data centers using VXLAN for network virtualization. It allows isolated Layer 2 segments (VLANs) to be stretched across Layer 3 boundaries while maintaining distinct VLAN IDs at each site.

  This approach is efficient for scaling large data center networks while avoiding VLAN ID exhaustion and enabling easier segmentation.

  In summary, the correct behavior, as per the exhibit and the detailed explanation, is that traffic sent from Server1 will be tagged with VLAN ID 200 when it reaches Server2 via leaf2. This ensures proper traffic segmentation and handling

  across the VXLAN-enabled data center network.

• Question 38:

  Exhibit.

  

  Referring to the exhibit, Host1 (10.1.1.1) is failing to communicate with Host2 (10.1.2.1) in a data center that uses an ERB architecture. What do you determine from the output?

  A. The traffic is failing because load balancing is not configured correctly.
  B. The traffic is entering the VXLAN tunnel.
  C. Host1 and Host2 are directly connected to leaf1.
  D. The irb.20 interface is not configured on leaf1.
  B. The traffic is entering the VXLAN tunnel.

  ---

  Explanation

  Understanding the Problem:

  Host1 (10.1.1.1) is failing to communicate with Host2 (10.1.2.1) within an EVPN-VXLAN environment using ERB architecture.

  Analysis of the Exhibit:

  The provided output includes information from the show route forwarding-table matching command for IP 10.1.2.1. The next hop is shown as vtep.32769, which indicates that the traffic destined for 10.1.2.1 is being forwarded into the VXLAN

  tunnel with the correct VTEP (VXLAN Tunnel Endpoint).

  Conclusion:

  Option B:Correct--The traffic from Host1 is entering the VXLAN tunnel, as evidenced by the next hop pointing to a VTEP. However, the issue could lie elsewhere, possibly with the remote VTEP, routing configurations, or the receiving leaf/

  spine devices.

• Question 39:

  What are three actions available tor MAC move limiting? (Choose three.)

  A. drop
  B. filter
  C. enable
  D. log
  E. shutdown
  A. drop
  D. log
  E. shutdown

  ---

  Explanation

  MAC Move Limiting:

  MAC move limiting is a security feature used in network switches to detect and mitigate rapid changes in MAC address locations, which could indicate a network issue or an attack such as MAC flapping or spoofing.

  When a MAC address is learned on a different interface than it was previously learned, the switch can take various actions to prevent potential issues.

  Available Actions:

  A. drop:This action drops packets from the MAC address if it violates the move limit, effectively blocking communication from the offending MAC address.

  D. log:This action logs the MAC move event without disrupting traffic, allowing network administrators to monitor and investigate the event.

  E. shutdown:This action shuts down the interface on which the MAC address violation occurred, effectively stopping all traffic on that interface to prevent further issues.

  Other Actions (Not Correct):

  B. filter:Filtering is not typically associated with MAC move limiting; it generally refers to applying ACLs or other mechanisms to filter traffic.

  C. enable:This is not an action related to MAC move limiting, as it does not represent a specific reaction to a MAC move event.

  Data Center

  References:

  MAC move limiting is crucial for maintaining network stability and security, particularly in environments with dynamic or large-scale Layer 2 networks where MAC addresses might frequently change locations.

• Question 40:

  You are asked to interconnect two of your company's data centers across an IP backbone. Both data centers require Layer 2 and Layer 3 connectivity. In this scenario, which three actions would accomplish this task? (Choose three.)

  A. Advertise Type 2 EVPN routes across the DCI.
  B. Ensure border leaf nodes in each data center can exchange EVPN routes.
  C. Ensure there is a full mesh of VTEPs between all spine nodes within both data centers.
  D. Advertise Type 5 EVPN routes across the DCI.
  E. Ensure there is a full mesh of VTEPs between all leaf nodes within data centers.
  A. Advertise Type 2 EVPN routes across the DCI.
  B. Ensure border leaf nodes in each data center can exchange EVPN routes.
  D. Advertise Type 5 EVPN routes across the DCI.

  ---

  Explanation

  Layer 2 and Layer 3 Connectivity Requirements:

  To interconnect two data centers across an IP backbone with both Layer 2 (L2) and Layer 3 (L3) connectivity, EVPN-VXLAN (Ethernet VPN with Virtual Extensible LAN) is the ideal solution. EVPN supports L2 VPNs while also enabling L3

  connectivity across multiple locations.

  Necessary EVPN Route Types:

  Type 2 EVPN Routes:These routes are used to advertise MAC addresses for Layer 2 connectivity. They are essential for enabling seamless L2 communication across data centers.

  Type 5 EVPN Routes:These routes are necessary for advertising IP prefixes for Layer 3 connectivity between data centers. They enable the exchange of L3 information across the IP backbone, ensuring routed traffic can reach its destination.

  Border Leaf Nodes:

  Border Leaf Nodes:Ensuring that the border leaf nodes (the entry and exit points for traffic between data centers) can exchange EVPN routes is critical for the correct dissemination of both L2 and L3 information across the data centers.

  Conclusion:

  Option A:Correct--Type 2 EVPN routes are required for Layer 2 MAC address learning and communication across the DCI (Data Center Interconnect).

  Option B:Correct--Border leaf nodes need to exchange EVPN routes to maintain connectivity between data centers.

  Option D:Correct--Type 5 EVPN routes are essential for Layer 3 connectivity across the DCI.

  Options and are incorrect because they refer to establishing full mesh VTEPs (VXLAN Tunnel Endpoints) C E across all spine or leaf nodes, which is unnecessary for the scenario provided. The focus should be on border leaf nodes and

  appropriate route advertisements for L2 and L3 connectivity.