If you want to learn about BGP, OSPF, and Data Center Networking, you’re in the right place. This blog covers Juniper Networks Certified Associate, Data Center (JNCIA-DC Exam), which covers networking topics. We will detail the exam topics and then give some tips and tricks for the examinees.
Table of Contents
- Overview of The JNCIA-DC Exam
- Prerequisites for the JNCIA-DC Exam
- JNCIA-DC Real Exam Questions
Overview of The JNCIA-DC Exam
Let’s begin with the things that the certification overview covers.
It’s a 65-question, multiple-choice JNCIA-DC Exam. It’s just a bunch of quizzes. There are no labs with the associate exams, just some multiple-choice mix-and-match. Sometimes, you get some diagrams or outputs of configurations, and you have to write down what’s happening or how to fix something. The exam duration is 90 minutes. But if you’re comfortable with the related stuff, it should take around 60 minutes to finish the exam. The exam is taken via Pearson VUE.
When it comes to preparing for the JNCIA-DC exam, there are few resources out there because it’s a relatively new certification. But the good thing is that Juniper has its learning portal with enough resources to pass the certification test. Most importantly, it’s completely free. You can take free, self-paced classes on JNCIA-DC. There are also vendor-led classes if you want to have an instructor throughout your journey. On that path, you’ll have to pay the vendors.
If you’re having headaches and thinking you don’t have enough resources at home to simulate a lab environment, Juniper also has you covered there. You can get hands-on experience completely free of charge via Juniper vLabs. In Juniper Labs, you can virtually simulate different instances of different types of devices. You also have access to look at some pre-configured labs. Of course, these will not match the actual configurations in the classes, but these will give you a rough idea about the labs.
Prerequisites for the JNCIA-DC Exam
Let’s talk about what is covered in the JNCIA-DC Exam. Some of the stuff there may be familiar to you. That’s why reviewing the modules and watching all the provided videos is worth it.
Firstly, you’ll need knowledge of Data Center Architecture. It covers traditional multi-tier architectures, Spine/Leaf IP-fabric architectures, Layer 2 and Layer 3 strategies, the basics of Overlay vs. Underlay networks, and the basics or purpose of EVPN/VXLAN. Then comes Layer 2 Switching, VLANs, and Security, where you must identify the concepts, operations, or functionality of Layer 2 switching for the Junos OS, such as Ethernet switching/bridging concepts and processes. You should be able to identify the concepts, benefits, or functionality of VLANs and Layer 2 security. You should also be able to describe how to configure, monitor, or troubleshoot Layer 2 switching, VLANs, or safety.
Next, Protocol-Independent Routing
For this section, you must be able to identify the concepts, operations, or functionality of various protocol-independent routing components. You must know about load balancing, static, aggregate, and generated routes. Then, you need to know the JNCIA-DC Exam or Data Center Routing Protocols like BGP/OSPF. In addition, you should be familiar with the configuration, monitoring, and troubleshooting of BGP and OSPF in a data center environment. This includes understanding the concepts of route redistribution, route summarization, and route filtering. Additionally, you should be able to identify the different types of BGP and OSPF authentication mechanisms and their importance in securing data center networks.
Finally, you must sit for the certification test after understanding the concepts of redundancy, fault tolerance, and failover mechanisms to ensure the continuous operation of critical services. Additionally, you should be familiar with the benefits of high availability, such as minimizing downtime, improving reliability, and ensuring seamless scalability for growing data center networks. Understanding the applications and requirements of high availability in areas like load balancing, virtualization, and disaster recovery is also essential for maintaining a resilient data center infrastructure.
You can look at the mega cheat sheet by John Berth to get a comprehensive idea about BGP here. It went through almost every part of it. It covered different BGP states, from idle to established. All the other attributes, BGP messages, and differences between internal and external BGP route selection.
JNCIA-DC Real Exam Questions
Q1. What are the two characteristics of a typical EBGP underlay fabric? (Choose two.)
- An EBGP fabric does not require an IGP to advertise loopback IPs.
- An EBGP fabric relies on an IGP to advertise loopback IPs.
- Each device in an EBGP fabric will be configured in its own unique private AS.
- Each device in an EBGP fabric will be configured to be part of the same private AS.
Ans: 1 & 3
Q2. Which statement about a five-stage IP fabric topology is correct?
- There is a maximum of five hops between any end devices.
- They are typically deployed in small to medium data centers.
- They are commonly referred to as interconnected data centers.
- There is a maximum of three hops between any end devices.
Explanation: Five-stage IP fabric topologies are typically deployed in large data centers. Also, they are not referred to as interconnected data centers. They have a maximum of five hops between any end devices.
Q3. Which statement is correct about IP fabric?
- The routing protocol in use offers load sharing.
- The entire IP fabric is one large broadcast domain.
- The underlying spanning tree protocol used provides loop prevention.
- Transit traffic is passed through the network based on the original frame’s destination MAC address.
Q4. How many stages are in the following IP fabric?
Q5. Which two protocols can you use for a data center underlay network? (Choose two.)
Ans: 2 & 3
Q7. Which two statements about the IP fabric below are correct? (Choose two)
- This is a five-stage IP fabric.
- This is a three-stage IP fabric.
- Only traffic between pods must traverse the super spine devices.
- All traffic must traverse the excellent spine devices.
Ans: 1 & 3
Q8. What must be done to make the figure below a valid IP fabric?
- Remove the connection between the leaf nodes.
- Add a connection between the spine nodes.
- Add two connections between the spine nodes.
- Remove one of the redundant links between a leaf node and a spine node.
Q9. How many broadcast domains are present in the below topology?
Explanation: Collision domains are individual physical connections that come from the switch. If it’s a hub, all the connections there would be counted as a single collision domain. When it comes to controls, each physical interface is its collision domain. Every VLAN is its broadcast domain. So, looking at the given topology, there’s only one VLAN used, so there is one broadcast domain.
Q10. How does a Layer 2 switch populate its bridge table?
- It stores the source MAC address of frames traversing the network.
- It stores the protocol number of frames traversing the network.
- It holds the destination MAC address of frames traversing the network.
- It keeps both source and destination MAC addresses of frames traversing the network.
Q11. What happens if a frame with a known destination MAC address enters a switch?
- The MAC address is added to the bridge table.
- The ingress PFE sends the header information to the RE.
- The egress PFE performs a MAC address lookup and determines the ingress PFE and port.
- The ingress PFE performs a MAC address lookup and determines the egress PFE and port.
Q12. Which two statements are factual with regards to MACset?
- It does not provide authentication for Ethernet traffic between two network nodes.
- It provides authentication for Ethernet traffic between two network nodes.
- It does not offer encryption for Ethernet traffic between two network nodes.
- It provides encryption for Ethernet traffic between two network nodes.
Ans: 2 & 4
Q13. You have configured a load-balancing policy. Which statement about applying the approach is correct?
- The policy is applied as an import policy under the routing protocol’s hierarchy.
- The policy is applied as an import policy under routing-options forwarding-table.
- The policy is applied as an export policy under the routing protocol’s scale.
- The policy is used as an import policy under the routing-options forwarding-table.
As shown in the figure below, you are configuring OSPF in your network. R1 has been configured with interface metrics. All other links in the network are using the default interface metric.
Q14. In this scenario, which OSPF interface on R1 will be preferred when routing traffic between R1 and R5?
- https://github.com/JohnBreth/CCNP-Labs/blob/master/BGP/BGPupdatedsmall.png (PNG won’t open directly, open on separate tab to github portal)