Crucial Drivers for Passing the Cisco 300-410 ENARSI Exam

The 300-410 ENARSI exam is required to obtain the CCNP Enterprise certification and also qualifies individuals for the Cisco Certified Specialist - Enterprise Advanced Infrastructure Implementation certification. It evaluates one's ability to implement and resolve complex issues related to advanced routing technologies and services such as VPN, Layer 3, infrastructure services, infrastructure security, and infrastructure automation.

The Cisco 300-410 exam lasts 1.5 hours and comprises 55-65 questions. It is available in both English and Japanese languages. Individuals can register for the exam through Pearson VUE, and the standard fee for taking the test is $300. They can take the exam either at a testing center or online.

Ways to Prepare for Cisco 300-410 ENARSI Exam

Sufficient preparation is necessary for the Cisco 300-410 ENARSI exam; individuals should approach it seriously. There are various study materials available to specialists, and below are some practical options they can explore:

1. Understand Cisco 300-410 ENARSI Exam Syllabus

The main priority for candidates is to become familiar with the topics covered in the Cisco 300-410 exam. They can achieve this by using the blueprint on the official website, which provides an overview of the domains tested. Using this information, candidates can identify their strengths and weaknesses and tailor their preparation process accordingly to focus on specific areas.

2. Enroll in a Training Course

Professionals can use the official training course to enhance their abilities in working with enterprise networks, implementing, configuring, and resolving issues. This training opportunity encompasses advanced infrastructure technologies and routing. More information about this course can be found on the Cisco website.

3. Learn from a Study Guide

The official study guide may be helpful for individuals who prefer to prepare for the certification exam independently and manage their own study time. Cisco Press's Official Cert Guide aims to help you study, prepare, and practice for the exam, to ensure you are fully ready for your certification test.

4. Try Out a Cisco 300-410 ENARSI Practice Test

Candidates may use Cisco 300-410 practice tests to become familiar with the question patterns of the actual exam beforehand. This is also an excellent opportunity to refine the skillset needed for the Cisco ENARSI exam.

5. Learn from Experts

Interacting with other test-takers aiming to excel in different exams and obtaining relevant certifications from various parts of the world is crucial. These individuals may have their tips and strategies for preparation, which can be beneficial to learn from through communication.

Key Motives to Pass the Cisco 300-410 Certification Exam

Obtaining the CCNP Enterprise certification by passing the 300-410 ENARSI and 350-401 ENCOR exams can provide numerous advantages. Here are how you can benefit:

It confirms your skills. Successfully passing the Cisco 300-410 exam indicates that you possess the essential competencies and understanding to implement and troubleshoot advanced routing technologies and services. Furthermore, the certification you receive proves to hire managers that you can perform intricate tasks. Many organizations are seeking individuals with these proficiencies.

It will broaden your knowledge. Passing the Cisco 300-410 ENARSI exam is not only about obtaining the certification but also an excellent opportunity to enhance your expertise in implementing and troubleshooting advanced technologies and services. As you undergo intensive preparation, you will gain a wealth of knowledge and acquire valuable skills.

Earning the Cisco 300-410 certification will increase your employment prospects. Individuals who hold Cisco certification are often more attractive to employers than those who do not have it. With CCNP Enterprise, you will have an advantage over job seekers who lack this certification, and employers may prefer to hire you for available positions.

The certification can bring a feeling of accomplishment, which is personally satisfying. The CCNP Enterprise certification can bring about a sense of personal contentment and accomplishment many aspire to attain. It can enhance the self-assurance of network administrators and IT professionals in their competence to create, diagnose, and implement networks and showcase their proficiency in this area.

Conclusion

If you aspire to progress in IT, consider taking the 300-410 ENARSI exam and earning a professional certification. Nonetheless, it's vital to adequately prepare for this test by using various resources, including the official training course, certification guidebook, practice tests, and more, and choosing the ones that align with your requirements. Once you've finished preparing, you can concentrate and confidently take the exam.

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Make your network yours with CML 2.5 annotations

Cisco Modeling Labs (CML) 2.5 arrives with annotations, a new feature for all CML license levels. When learning and designing, annotations let you get the most out of your labs. Annotations allow you to include all the documentation on how parts of the network work, details about your learning objectives and next steps, or ways the network elements fit together. In short, the annotations feature in CML 2.5 lets you make your network yours. Here’s how it works.

Add context with annotations in CML

Annotations allow you to provide additional context to your lab topology and organize the elements in a helpful, meaningful way. For example, you can use annotations to show routing, IP addressing, and VLAN information, as shown below: 

Annotations in CML are persistent. This means annotations will be included in the lab definition if exported, allowing you to share your annotated labs with others.  

A grid background and node/annotation grid snapping are enabled by default. Snapping will automatically snap nodes and annotations to ensure they are properly aligned when drawing or moving them. You can turn off snapping for a lab by unchecking the snap to grid option in the toolbar settings. You can also temporarily disable snapping by holding the Alt key when you add or move a node/annotation. 

Additionally, annotations support transparency and layering, allowing you to stack annotations.

How to add annotations to labs in CML 2.5

You can add annotations to labs in the workbench via one of the four annotation tools in the toolbar. 

 There is one tool for each type of annotation: 

◉ Rectangle  

◉ Ellipsis 

◉ Text 

◉ Line

For all annotation types except text, you can add the annotations by first selecting the tool. Then click and hold the mouse where you want the annotation to start, and drag it to where you want it to end. Releasing the mouse will create the annotation, and you will see a sidebar with other properties you can change for the annotation. 

The process of adding a text annotation is similar, starting with selecting the tool. Next, click and release where you want the text. Finally, the sidebar will open, allowing you to enter the text you wish to use. 

New options in toolbar settings

Click the gear icon in the toolbar to open the canvas settings menu, which provides these new options for CML 2.5: 

1. Toggles the grid on/off 

2. Turns node/annotation snapping on/off 

3. Turns annotations off, hiding the drawn annotations and annotation tools 

NOTE: You can temporarily disable the snap-to-grid option by holding the Alt key (or Option key on a Mac) when moving or resizing an annotation/node. This lets you keep snapping enabled while precisely placing an annotation/node.  

Edit annotations

Selecting an annotation will toggle the visibility of the resize handles for the currently selected annotation. Additionally, a sidebar will be opened, allowing you to edit the annotation properties further

1. Resize Handles 

2. Sidebar 

Future annotations in CML

The CML development team is currently exploring adding an image annotation type in a future release to allow the addition of images inside a topology. 

Source: cisco.com

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Something New: AP Discovery Methods for 6GHz Wi-Fi – Part 2

In Part 1 (Something Old) we looked at basic changes to the physical layer provided by wave 1 of 801.11ax, how these changes can affect performance, and how OFDMA enables the optimal use of the 6GHz spectrum. In this second article, we’ll explore “something new:” the challenges of discovery in 6GHz, new methods used for solving this, and how these new methods open 6GHz for many different use cases.

Is There Anybody Out There?

In previous generations, Wi-Fi clients would scan channels and send unsolicited probe requests to discover access points (APs). Scanning channels can be a timely process as beacons are only broadcast every 102400us so the client must dwell long enough to detect the beacon. At 6GHz this is 102400us x 59 channels (there are 59 20MHz channels in the new 6GHz spectrum) which is over 6 seconds. For the client, this loss in time represents a disruption in communication. Creating intolerable latency in voice and lost opportunity to hundreds of megabytes of data every time the client decides to scan. Furthermore, the previous process would be to send unsolicited probe requests (wildcard requests) to see how APs would respond. Now, remember, this is all a contention-based medium, so these probe requests and responses on every channel for every client create a significant amount of interference and at the very least, inefficient use of the spectrum.

Read More: 300-710: Securing Networks with Cisco Firepower (SNCF)

Over the years the IEEE has introduced measures to address these roaming challenges. 802.11k was introduced to provide clients with a list of neighboring APs, 802.11v was introduced to provide a recommended AP candidate, and 802.11r was introduced to reduce the roaming time for 802.1x clients. Not all clients and infrastructure support these measures so while they helped, they did not eliminate the need for clients to send unsolicited probes.

While these IEEE updates are still available for 6GHz, the strategy for AP discovery fundamentally changes. To start with, unsolicited probe requests are no longer allowed (with one limited exception we will discuss shortly).

Three New Methods to Improve AP Discovery

Since we have already established scanning channels at 6GHz is not allowed, there are three new methods introduced in Wi-Fi 6E for finding AP candidates.

The primary method (and the one that clients typically respond to best) is called Reduced Neighbor Report (RNR). Since most, if not all, clients will have legacy band capability, there is an Information Element (IE) embedded in the legacy band beacons that list the 6GHz SSID(s) that are available on the serving AP. The client first scans the 5GHz or 2.4GHz channels and looks for this RNR element. The RNR report contains information about the 6GHz channel, SSID, BSSID, a bit of information on the AP, and the allowed power levels (Power Spectral Density). This effectively makes the 2.4GHz and 5GHz channels a control channel for the 6GHz. Clients can then send a directed probe request to those channels that are learned in the RNR to determine which 6GHz AP to join. It is important to note there can be multiple 6GHz SSIDs included in the RNR and they do not have to match the legacy SSIDs.

The information contained in an RNR is very similar to the information provided in the previously introduced 802.11v action frame. The RNR below is from a 5GHz beacon and is advertising two SSIDs on the 6GHz channel number 5. The legacy 802.11v action report below shows similar information to the RNR but the fundamental difference is twofold:

◉ This is an action frame not part of the beacon like the RNR. It is a request-response type transaction. An RNR is broadcast in the legacy band beacons.

◉ The information in the 802.11v action frame contains information about other APs on the same frequency band. The RNR only lists SSIDs broadcasted from the 6GHz band (different frequency band) as this same AP.

Figure 1: RNR on 5GHz beacon

Figure 2: 802.11v Action Frame

What if the AP is only broadcasting 6GHz? This is an unlikely condition, but nonetheless a potential one. First, scanning can be reduced by limiting the number of channels to be scanned. This is called Preferred Scanning Channels (PSC). The PSCs are the primary channels (20MHz subchannel) of the 80MHz channels. This works well since 80MHz will often be the preferred bandwidth to operate for reasons previously discussed in part 1 of this blog series. If however, lower bandwidth channels are used without RNR or additional support from the methods below, it would be very easy for a client to miss this channel which should be a consideration when using PSC with narrower band channels.

Figure 3: Preferred Scanning Channels (red)

There are two mutually exclusive options to further enhance the AP discovery in which the AP will broadcast messages an additional 4 times between the beacons or about every 20ms (configurable from 5ms to 25ms). The first method is called Fast Initial Link Setup (FILS) and is based on a previous standard of 802.11ai. This is a very lightweight message (somewhere around 100 bytes as compared to a beacon which is 500+ bytes). The second method is called “Broadcast Probe Response” or “Unsolicited Probe Response” (UPR). Like FILS, this advertisement will be broadcast at a higher rate than the beacon. However, the UPR broadcasts everything in the probe response so while it supplies the client with more information, it is a bit heavier in the amount of data transmitted repeatedly.

Teamwork Makes the Discovery Dream Work

So how do these four methods work together? First, if there are legacy band SSIDs transmitted on the AP the expectation is that the RNR will do the work of discovering the 6GHz channel, and no other method is required. In the case where only 6GHz is broadcast from the AP the most likely scenario would be the use of PSC with either FILS or UPR. Notice UPR and FILS are exclusive options, you can only use one or the other. Early testing of client devices has seen some issues with 6GHz standalone APs not being discovered with only PSC and it is needed to have FILS (or UPR) enabled to assist a client in discovering the AP. This may change over time but for the early implementations, deploying 6GHz with only 80MHz channels and PSC enabled is a good option. This allows the primary channel to match the PSC channels. In addition, enabling FILS can provide further assistance for discovery with minimal impact on performance.

Source: cisco.com

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Wi-Fi 6E, Something Old, Something New, Something Borrowed, Something Blue – Part 1

With the recent release of a number of Wi-Fi 6E-enabled devices at the Consumer Electronics Show (CES), now is a good time to take into account some of the benefits that Wi-Fi 6/6E provides. Wi-Fi 6/6E was not an “incremental” change, it was a major leap forward with the new innovations and most importantly, the addition of the newly allocated 6GHz spectrum (which varies across regions). In this series, we will provide the reader with an in-depth understanding of some of these advanced features in Wi-Fi 6 and how some of these features benefit them. Furthermore, we will discuss some of the new innovations built around the Wi-Fi 6E standard and how IT leaders are just starting to realize the potential for 6GHz wireless.

“Something Old”

While the ability to support multiple simultaneous users has been available prior to Wi-Fi 6E this is one “old” feature that becomes enhanced in Wi-Fi 6E. In part 1 we want to look at some of the changes to the physical layer, what changed, and how this helps your WiFi performance.

Of all the features added to Wi-Fi 6, one, in particular, will have a very significant effect on the new 6GHz band and deserves some in-depth consideration and that is OFDMA. Remember all that old 802.11ax optional capability is now mandatory at 6GHz as there is no requirement for brownfield support. There were other technologies added to the legacy bands in Wi-Fi 6 that really paved the way for substantial improvements in performance. For example, increased modulation rates (up to 1024 QAM, think of this as higher maximum throughput), better spatial isolation (BSSID Coloring/OBSS and multiple timers for IBSS and OBSS, think of this as better performance in an area with lots of clients and APs), Target Wait Time (better battery life for clients), and others.

Digging into OFDM – The Virtual Wires of Wi-Fi

OFDM is the “baseband” signal which is the underlying waveform that is used to generate the RF signal we think of as Wi-Fi from the digital input. This baseband signal is comprised of multiple “tones”. The combination of these tones is called Orthogonal Frequency Division Multiplexing (OFDM). Each tone is orthogonal to the other tones which means the information on that tone can be detected with limited interference from other tones even though they are tightly spaced together. Think of each of these tones as a wire that information can be conducted. Fewer tones mean fewer wires but higher throughput for any one wire, more tones mean more wires but lower throughput per wire. The total “available” throughput, in either case, ends up being basically the same. In 802.11ax a change was made to move from 64 tones to 256 tones (4x) in a 20MHz channel.

Figure 1. OFDM changes from Wi-Fi 5 to Wi-Fi 6

As discussed, this increase in tones has very little impact on the link available throughput but, there are other trade-offs. First, the 4x increase in tones improves the robustness of multipath (improved resistance to inter-symbol interference) but loses some effectiveness in a high-speed mobile environment (doppler shift). So, under typical indoor use, we get a benefit of a more reliable connection. The second, and biggest change is the ability to better “sub-channelize” the physical layer. This access method is called Orthogonal Frequency Division Multiple Access or OFDMA. A sub-channel or group of tones at a given time slot is considered a “resource unit” often referred to as an “RU”.

Since the ratio of the number of tones is relative to the bandwidth, in a 20MHz channel there can be up to 9 RUs (26 tone groups) for any one frame and in a 160MHz channel this could go up to 74 RUs (notice this is not 72 as there are some efficiencies due to higher ratio of usable tones at higher bandwidths). RUs can come in larger sizes also to match the resource demand. For example, with a 20Hz channel, you can additionally have 52 tones, 106 tones, or the full band on 242 tones. Furthermore, you can to some degree mix and match these different-sized RUs in the same frame. These RUs provide a mechanism to transmit to multi-users (MU) at the same time without having to rely on spatial diversity. Let’s put a number to why this is important. Take a 64-byte packet operating at some typical rate like 256 QAM with ¾ rate coding (MCS8). With 40MHz channels, one slot is capable of around 380 bytes. What happens if a 64-byte packet (typical packet) is transmitted over this 40MHz channel? Less than 20% of the channel is used, and over 80% of that resource is wasted! With the use of RU’s, we can send multiple packets at the same time and pretty much eliminate that inefficiency. Granted not all packets are 64 bytes but larger packets are broken into smaller physical layer packets called Protocol Data Units (PDUs) to be transmitted and again will not fill up the entire spectrum for all PDUs.

So how does the AP signal the client when and where its RUs are allocated since there are now multiple client packets in a time slot? This is accomplished using two mechanisms. First, there is now a new field in the preamble that provides the “where” called SIG-B. This field provides how the resource units are allocated over the slot and the per-client information that specifies which resource units are allocated for my specific client.

There are really 3 options to transmit multi-user packets at the same time:

◉ Multiple simultaneous users’ signals are transmitted using the full band but the spatial characteristics of the channel allow them to communicate with limited interference (spatial separation).

◉ Multi-User with different users assigned to different RUs (frequency separation).

◉ A combination of both.

Option 1 is a multiplier – If the channel permits sending multiple streams over the same channel the capacity of the channel grows proportional to the number of users. There are limitations to this, for example, the number of uplink spatial streams is equal to or less than the number of uplink receivers in the access point. If the AP and the environment support option 1 it would typically be used.

Option 2 is an optimization – If the network has multiple clients that support Wi-Fi 6 that have traffic to send at the same time the network will optimize by sending the traffic at the same time.

The second function that facilitates the “when” the use of multiple clients is the “trigger frame”. When the AP is ready for the clients to simultaneously send uplink information it transmits a trigger frame with the client information. The client waits for one short interframe spacing (SIF) and then transmits the uplink data on the appropriate RUs. The AP can then send back a “multi-Station ACK” allowing the multiple client uplink packets to be acknowledged simultaneously. Uplink ACKs are transmitted similarly to the uplink data with a trigger frame on the allocated RUs.

Figure 2. Trigger Frame Sequence

Given 6GHz has a much larger block of spectrum and the most common FCC regulation to deploy is based on power spectral density (PSD), which allows for more power with wider channels, it is expected that most deployments will use 80MHz or 160MHz (see 6-GHz Unlicensed Spectrum Regulations and Deployment Options White Paper). With the previous generation of one packet per time slot, 80MHz channels became very inefficient, and hence why you rarely saw this type of operation for multiple access. With 802.11ax the ability to do both frequency and spatial division, the clients can be assigned only the resources necessary for their needs no matter how wide the channel is thus making the use of these wider channels much more effective. In the 2.4GHz and 5GHz bands clients capable of supporting OFDMA had to contend for a slot with legacy clients and of course since it requires more than one client to participate in “multiple access” it would only contend for a multiuser slot if there were multiple clients that could support OFDMA with packets to transfer. At 6GHz all clients support OFDMA and hence no need to contend with legacy clients for access, every slot can transmit multiple packets. With the addition of the 6GHz channels, we will just now begin to fully benefit from the use of OFDMA.

With Wi-Fi 6 the link can now be divided into both bandwidth and time so specific chunks of resources can be “scheduled” for delivery further improving efficiency and latency (see Figure 2 below).

In addition to the improvement of efficiency in the wider band channels the “triggered multi-user access” allows for the scheduling of packets in a much more predictable manner. The 802.11ax standard does not dictate all the necessary details for managing the packet scheduling and hence this is an area where there can be some differentiation in performance between implementations. Cisco, a company with a rich history of packet scheduling and optimization is obviously exploring this area also. For example, in the data below we can see the latency comparison between a typical Wi-Fi 5 network, a Wi-Fi 6 network, and a Wi-Fi 6 network with optimization in scheduling. Notice with Wi-Fi 6 there is a substantial reduction in outlying packets exceeding the 25ms delay bound and with some optimization, a further reduction in latency can be seen. This is an example of the value of optimized scheduling with 802.11ax multi-user capability provides.

Figure 3. Packet Scheduling Improvements

Wi-Fi 6E provided a leap forward in capability. Some we could not fully recognize until 6GHz was made available. Benefits in capacity, latency, and stability are all a part of the 802.11ax update. In addition, vendors like Cisco can provide optimized packet scheduling to further enhance the user’s experience. Deploying Wi-Fi 6E capable access points will allow the operator to begin to experience these significant new enhancements in performance.

Source: cisco.com

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Networking Demystified: The Modern Networking Stack

Suppose you were to peruse any book or paper on the topic of computer networking. In that case, you will undoubtedly find at least a cursory mention of the OSI or TCP/IP networking stack. This 7 (or 5) layers model defines the protocols used in a communication network, described in a hierarchy with abstract interfaces and standard behaviors. In this “Networking Demystified” blog post, we shed light on the modern networking stack but from a completely different vantage point: the focus will be on the technologies and areas associated with the various layers of the stack. The goal is to offer a glimpse of what engineers and technologists are working on in this exciting and continuously evolving space that impacts businesses, education, healthcare, and people worldwide.

But first, how did we get to where we are today?

A Brief History of Time (well, … networking mostly)

The early years of networking were all about plumbing: building the pipes to interconnect endpoints and enable them to communicate. The first challenges to conquer were distance and reach—the connection of many devices—which gave rise to local area networks, wide area networks, and the global Internet. The second wave of challenges involved scaling those pipes with technologies that offered faster speeds and feeds and better reliability.

The evolution in Physical and Link Layer technologies continued at a rapid cadence, with several technologies getting their 15 minutes of fame (X 25, Frame Relay, ISDN, ATM, among others) over the years and others ending up as roadkill (which shall remain unnamed to protect the innocent). The Internet Protocol (IP) quickly emerged as the narrow waist of the hourglass, normalizing many applications over several link technologies. This normalization created an explosion in Internet usage that led to the exhaustion of the IPv4 address space, thereby bringing complexities like Network Address Translation (NAT) to the network as a workaround.

The years that followed in the evolution of networking focused on enabling services and applications that run over the plumbing. Voice, video, and numerous data applications (email, web, file transfer, instant messaging, etc.) converged over packet networks and contended for bandwidth and priority over shared pipes. The challenges to overcome were guaranteeing application quality of service, user quality of experience, and client/provider service level agreements. Technologies for traffic marking (setting bits in packet headers to indicate the quality of service level), shaping (delaying/buffering packets above a rate), and policing (dropping packets above a guaranteed rate), as well as resource reservation and performance management, were developed. As networks grew more extensive, and with the emergence of public (provider-managed) network services, scalability and availability challenges led to the development of predominantly Service Provider oriented technologies such as MPLS and VPNs.

Then came the things… the Internet of Things, that is. The success of networks in connecting people gave rise to the idea of connecting machines to machines (M2M) to enable many new use cases in home automation, healthcare, smart utilities, and manufacturing, to name a few.  This, in turn, presented a new set of challenges pertaining to constrained devices (i.e., one with limited CPU, memory, and power) networking, ad hoc wireless, time-sensitive communication, edge computing, securing IoT endpoints, scaling M2M networks, and many others. While the industry has solved some of these challenges, many remain on the plates of current and future networking technologists and engineers.

Throughout this evolution, the complexity of networks continued to grow as IT added more and more mission-critical applications and services. Every emerging innovation in networking created new use cases that contributed to more significant network usage. The high-touch, command-line interface (CLI) oriented approach to network provisioning and troubleshooting could no longer achieve the scalability, agility, and availability demanded by networks. A paradigm shift in the approach to network operations and management was needed.

Cue the Controllers

Network management systems are not a new development in the history of networking. They have existed in some form or fashion since the early days. However, those management controls operated at the level of individual protocols, mechanisms, and configuration interfaces. This mode of operation was slowing innovation, increasing complexity, and inflating the operational costs of running networks. The demand for networks to meet business needs with agility led to the requirement for networks to be software-driven and thus programmable.

This change led to the notion of Software-Defined Networks (SDN). A core component of a Software-Defined Network is the controller platform: the management system that has a global view of the network and is responsible for automating network configuration, assurance, troubleshooting, and optimization functions. In a sense, the controller replaces the human operator as the brain managing the network. It enables centralized management and control, automation, and policy enforcement across network environments. Controllers have southbound APIs that relay information between the controller and individual network devices (such as switches, access points, routers, and firewalls) and northbound APIs that relay information between the controller and the applications and policy engines.

Controllers originally were physical appliances deployed on-premises with the rest of the network devices. But more recently, it is possible for the controller functions to be implemented in the Cloud. In this case, the network is referred to as a cloud-managed network. The choice of cloud-managed versus on-premises depends on several factors, including customer requirements and deployment constraints.

Figure 1: Modern Networking Stack

So now that we have a historical view of how networking has evolved over the years let’s turn to the modern networking stack.

From Silicon to the Cloud

The OSI and TCP/IP reference models only paint a partial picture of the modern networking stack. These models specify the logical functions of network devices but not the controllers. With networks becoming software-defined, the networking stack spans from silicon hardware to the cloud. So, building modern networking gear and solutions has become as much about low-level embedded systems engineering as it is about cloud-native application development.

First, let’s examine the layers of the stack that run on network devices. The functions of these layers can be broadly categorized into three planes: data plane, control plane, and management plane. The data plane is concerned with packet forwarding functions, flow control, quality of service (QoS), and access-control features. The control plane is responsible for discovering topology and capabilities, establishing forwarding paths, and reacting to failures. In comparison, the management plane focuses on functions that deal with device configuration, troubleshooting, reporting, fault management, and performance management.

Data Plane

Engineers focusing on the data plane work on or close to the hardware (e.g., ASIC or FPGA design, device drivers, or packet processing engine programming). One of the perennial focus areas in this layer of the stack is performance in the quest for faster-wired link speeds, higher wireless bandwidth, and wider channels. Another focus area is power optimization to achieve usage-proportional energy consumption for better sustainability. A third focus area is determinism in latency/jitter to handle time-sensitive and immersive (AR/VR/XR) applications.

Control Plane

Engineers working on the control plane are involved with designing and implementing networking protocols that handle topology and routing, multicast, OAM, control, endpoint mobility, and policy management, among other functions. Modern network operating systems involve embedded software application development on top of the Linux operating system. Key focus areas in this layer include scaling of algorithms; privacy and identity management; security features; network time distribution and synchronization; distributed mobility management; and lightweight protocols for IoT.

Management Plane

Engineers working on the management plane work with protocols for management information transfer, embedded database technologies, and API design. A key focus area in this layer is scaling the transfer of telemetry information that needs to be pushed from network devices to the controllers to enable better network assurance and closed-loop automation.

Understanding the Controller Software Stack

Next, we will look at the layers of the stack that run on network controllers. Those can be broadly categorized into four layers: the runtime environment layer, the control layer, the assurance layer, and the northbound API layer.

◉ The runtime environment layer is responsible for the lifecycle management of all the software services that run on the controller, including infrastructure services (such as persistent storage and container/VM networking) and application services that are logically part of the other three layers.

◉ The control layer handles the translation and validation of user intent and automatic implementation in the network to create the desired configuration state and enforce policies.

◉ The assurance layer constantly monitors the network state to ensure that the desired state is maintained and performs remedial action when necessary.

◉ The northbound API layer enables the extension of the controller and integration with applications such as trouble-ticketing systems and orchestration platforms.

State-of-the-art controllers are not implemented as monolithic applications. To provide the required flexibility to scale out with the size of the network, controllers are designed as cloud-native applications based on micro-services. As such, engineers who work on the runtime environment layer work on cloud runtime and orchestration solutions. Key focus areas here include all the tools needed for applications to run in a cloud-native environment, including:

◉ Storage that gives applications easy and fast access to data needed to run reliably,

◉ Container runtime, which executes application code,

◉ Networks over which containerized applications communicate,

◉ Orchestrators that manage the lifecycle of the micro-services.

Engineers working on the control layer are involved with high-level cloud-native application development that leverages open-source software and tools. Key focus areas at this layer include Artificial Intelligence (AI) and Natural Language Processing (NLP) to handle intent translation. Other critical focus areas include data modeling, policy rendering, plug-and-play discovery, software image management, inventory management, and automation. User interface design and data visualization (including 3D, AR, and VR) are also crucial.

Engineers developing capabilities for the assurance layer are also involved with high-level cloud-native application development. However, the focus here is more on AI capabilities, including Machine Learning (ML) and Machine Reasoning (MR), to automate the detection of issues and provide remediation. Another center of attention is data ingestion and processing pipelines, including complex event processing systems, to handle the large volumes of network telemetry.

Engineers working on the northbound API layer focus on designing scalable REST APIs that enable network controllers to be integrated with the ecosystem of IT systems and applications that use the network. This layer focuses on API security and scalability and on providing high-level abstractions that hide the complexities and inner workings of networking from applications.

It’s an Exciting Time to be in Network Engineering

As networking evolved over the years, so did the networking stack technologies. What started as a domain focused primarily on low-level embedded systems development has expanded over the years to encompass everything from low-level hardware design to high-level cloud-native application development and everything in between. It is an exciting time to be in the networking industry, connecting industries, enabling new applications, and helping people work together where ever they may be!

Source: cisco.com

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Deploying the Wi-Fi Network at Cisco Live EMEA 2023

It is now the fourth time in a row that I had the chance to be part of the Cisco NOC team for Cisco Live EMEA.

If we go even further back in time, I had the chance to go to Cisco Live for the Technical Design Clinics back in London and Berlin. The pressure was on the shoulders of the NOC team who had to deliver a working Wi-Fi network with so many random client devices connected. I did not envy their position (although I admired it). I particularly remember a bug from smartphone vendors in Cisco Live London that was repeating the event SSID as a personal hotspot, causing a lot of trouble to other client connectivity. This was the year the CiscoLive SSID went from fully open to a pre-shared key SSID to prevent that type of problem.

End of 2017, the NOC team invited me to be part of the Wireless Controller team for Cisco Live Barcelona 2018. I accepted quickly mostly for the sake of being part of the Cisco Live event, which I consider a privilege. I discovered since then how setting up a large events network is such a unique endeavor and will try to give some insights into certain choices and decisions.

The Planning

Around summer the year before the event, the first meetings start. We set up a team and make sure we have the best people for the job at every position. This is the responsibility of Remco Kamerman, the Cisco Live NOC team lead and pretty much the only fixed team member since he recruits the rest of us. Some people from the software engineering teams, some salespeople, and some CX people (TAC, Customer Success, and Professional Services): team members are not picked for their job role but for their expertise. If you are one of the top people in your technology, chances are that you already know a good part of the NOC team for having worked with them throughout the year since they are the top people too.

Mapping Madness

We receive the venue plans and event blueprints early on but they keep changing until the very last day (less and less as time goes by of course). This is the challenge of the design folks in the team (Professional Services and System Engineers mostly) who have to do a wireless design mostly by looking at regularly changing plans. A few site visits were organized to get a feeling of the venue. I was there on the first day the building team started building for the event and can testify that the number of physical changes the venue goes through in just a couple of days is unthinkable if you are not used to such events.

Maps are an important part of managing a wireless network. We could leverage the interoperability between the venue maps on the RAI Prime Infrastructure appliance, the Cisco DNA Center we used for the event, and the Ekahau design software we used for the design. Maps were cross-imported between those 3 places so that we could have the proper maps for design and day-to-day management.

Keynote Design

A specific challenge was the keynote area which consisted of 4500 chairs around a central stage in an empty hall. 50 9104 stadium antennas were used to provide coverage from the trusses. Mounting those APs/antennas required very close collaboration with the keynote area build team as there are specific moments where the truss is down and accessible and then brought up (after which you need a scissor lift to access it and you want to avoid that as much as possible for efficiency)

The Build Up

The majority of the NOC team consists of people actually physically building up the network. That requires deploying hundreds of switches throughout the venue and the cabling that goes with that without anything visible to the naked eye. It also requires deploying hundreds of wireless access points in various places. They can be on poles, walls, or ceilings, and mounting elegantly and efficiently becomes an art.

Figure 1: Mounting APs and antennas on the structure

Similar to the Fira Barcelona, we inherited around 400 Wi-Fi access points from the RAI Amsterdam venue. They were nice enough to let us control their access points for the duration of the event. This way, we don’t have to deal with two separate wireless networks. A good part of the venue APs were Cisco 9120s with directional antennas mounted on the very high ceiling (as well as some 9104s in one Hall) which are perfect for providing general coverage.

Indeed the RAI hosts a lot of different shows that have nothing in common (Cisco Live was between a horse show and a pregnancy-related show) and their Wi-Fi network needs to stay stable between events. However, since we are Cisco and we are willing to deploy a network just for our own event, we could add access points at the ground level and be better oriented for specific applications (in general, the close the AP is to the clients, the better, if you can afford it). We knew the high-density areas and more complicated ground areas where additional coverage would be welcome and that’s what our design consisted of.

Figure 2: 9104 stadium antennas mounted on a truss that will go up in the Keynote area

Event Wi-Fi Choices

Historically, the main SSID is WPA2 PSK SSID and the organization prints the key on the event badge everyone wears. We added EduRoam support for our education customers to have an SSID their device already knows and can connect to, using their education credentials. We also added OpenRoaming, where your device automatically connects to the Wi-Fi as soon as you enter the venue if you already had an OpenRoaming profile installed on your device. If you didn’t you can install one from the CiscoLive event app. Personally, I installed an OpenRoaming profile on my iPhone after my local supermarket created a profile for me from their app. My phone automatically connected, in a secure and transparent manner, to the venue as soon as I arrived with my profile from my local supermarket thanks to the RAI also having an OpenRoaming SSID even before Cisco arrived onsite.

We definitely wanted to keep the number of SSIDs offered as low as possible to avoid confusion and to keep the wifi network efficiency to the maximum possible, but the convenience (and the security!) of OpenRoaming and Eduroam convinced us to offer those as extra services.

Wi-Fi 6E

This year, we wanted to offer 6ghz Wi-Fi as 6E is the newest coolest thing. The difficulty is that providing this across the whole event would have meant purchasing hundreds of 9166 access points. This is not possible as we prioritize customer deliveries for the first time on a new device. It would also have meant replacing all the venue APs which is impractical for us. We then covered the entire Meeting Village hall with the 40 9166 we had. The challenge with this hybrid approach is that Wi-Fi 6E requires WPA3 and we did not want to make the main SSID WPA3 yet.

Even if the CiscoLive population is typically nerdy (it’s a compliment nowadays I think) and well equipped, you wouldn’t believe some of the older devices that connect to the network and WPA3 support is just not at 100% yet we believe. We had to create a separate WPA3 SSID which was broadcasted both in 5Ghz and 6Ghz (but 6ghz being only available in the Meeting Village) for compatibility reasons.

Legacy and “Bells and Whistles” SSIDs

As a general rule, is good practice to have some kind of legacy SSID and some kind of more performing SSIDs with more bells and whistles. Some years ago, it meant we provided a Cisco Live Legacy SSID which existed on 2.4ghz, while the 5Ghz was the main and “cool” SSID.

In Cisco Live 2023, we completely gave up on 2.4ghz and the CiscoLive SSID was only available on 5Ghz. This meant the main CiscoLive SSID needed to have the most compatible settings to ensure all the clients could connect and that meant giving up on some great Cisco features (like Device Analytics) for the sake of maximum compatibility. I predict that very soon, the WPA3/6Ghz SSID will become the main SSID and the 5Ghz-only/WPA2 SSID will be the legacy one. Maybe too early for that to happen next year but why not 2025?

How the Event Went

Keynote and 6ghz

The event went very well overall. During the keynote or the party, throughput tests returned surprisingly good results. The 9104 antennas were really surprised by their well-defined coverage area with very small leakage outside of the coverage direction. This really helps with channel reuse in a large venue hall.

It was a good surprise to see more than 60% of the Wireless clients using Wi-Fi 6. However, only a few dozen supported 6E. We expect a sharp increase by next year, but it will stay a minority of clients. There were a couple of 802.11n clients but really not many.

The top simultaneous client count was around 13 500. It is slightly lower than the last event in Barcelona. We expect the event to grow by next year since this was the first one post-Covid.

Figure 3: Our custom telemetry graph

Hardware and Software Considerations

It was the first Cisco Live we ran 100% on the Catalyst 9800 in EMEA and 100% on Cisco DNA Center. Indeed in 2020, they were there but we still had 8540 WLCs in the network. We ran the 17.9.2 CCO software and only had minor issues to report. As is becoming more and more commonplace, most of the time we spent troubleshooting was on interoperability issues with specific device types and features. Completely disabling 2.4Ghz was a great idea because we noticed an increased usage of Bluetooth among the attendees and the Wi-Fi network would have disturbed all those Bluetooth devices.

Not everything was perfect though, it can never be in such a large event with so many new technologies. But I’m glad we keep improving year after year. There are always areas of complaint when the client density is higher than what we anticipated: there were some very successful sessions in Devnet theater or World of Solutions and connectivity was subpar during those events. We’ll make sure to come up with an improvement plan for next year to make that better.

Source: cisco.com

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Is Passing Cisco 300-415 ENSDWI Exam Worth Effort?

IT professionals highly covet the CCNP certification from Cisco. It confirms that a person has the necessary abilities and expertise to work with intricate networks by designing, setting up, configuring, and solving issues. The Cisco CCNP Enterprise certification includes the 300-415 ENSDWI exam.

The Cisco 300-415 ENSDWI exam concentrates on the technologies necessary for safeguarding business networks.

Cisco 300-415 ENSDWI Exam Information

The CCNP 300-415 Exam from Cisco is highly renowned and widely taken. It evaluates a person’s proficiency and expertise in configuring, handling, and fixing issues with Cisco networks.

The CCNP 300-415 exam is demanding and necessitates extensive preparation. Candidates must fully grasp the exam’sexam’s topics before attempting it. In addition to studying, candidates must also possess practical experience in dealing with Cisco networks.

You will need to pay $300 to take the exam and have 90 minutes to finish it. The exam is available in both Japanese and English. Cisco exams hold their validity for three years for associate and professional levels and two years for expert levels.

Pearson VUE conducts the CCNP 300-415 exam, and candidates can register via their website. The exam includes 55-65 multiple-choice and simulation questions, and candidates are allowed two hours to complete the exam.

Cisco 300-415 ENSDWI Exam Objectives:

Architecture (20%)

Controller Deployment (15%)

Router Deployment (20%)

Policies (20%)

Security and Quality of Service (15%)

Management and Operations (10%)

Tips for Cisco 300-415 ENSDWI Exam Preparation

Individuals who pass the Cisco 300-415 exam are awarded the esteemed Cisco Certified Specialist - Enterprise SD-WAN Implementation certification. However, before preparing for this certification exam, students should take note of the following:

Check out these five pointers that can assist you in passing the 300-415 ENSDWI exam on your initial attempt:

Comprehend the Exam

Register for Formal Training

Practice Continuously!

Sharpen Your Practical Abilities

Search and Join an Online Community

Before obtaining any study materials, registering for training, or buying exam preparation resources, it is recommended that you review the exam objectives. This will provide you with an understanding of the extent and complexity of the exam.

Once you clearly understand the exam objectives, you should select an appropriate training method (such as self-study or formal training). It is highly recommended to choose instructor-led training, as it allows interaction with experienced instructors and skilled professionals in passing the Cisco 300-415 exam.

Unfortunately, some candidates rely solely on study notes when preparing for the Cisco 300-415 ENSDWI exam. However, you require more than notes to pass this exam successfully. It is crucial to spend ample time practicing and mastering the intricacies of the exam curriculum. Therefore, seeking out and accessing online practice exams is advisable to make your preparation more dynamic. One such resource is the nwexam that provides practice questions, which can help you evaluate your level of readiness.

Technical skills are a significant part of the Cisco 300-415 ENSDWI exam. Thus, setting up a lab environment to refine the hands-on skills required for the exam is essential. By doing this, you can enhance your likelihood of passing the exam and gain proficiency in applying the acquired skills in practical situations.

Lastly, numerous online forums are available on the internet, allowing you to connect with other candidates preparing for the Cisco 300-415 ENSDWI exam. You can benefit from these forums by obtaining relevant study resources and other preparation tools from those who have already succeeded in passing the certification test.

Benefits of Becoming Cisco Certified

1. Skilled and Expert in the Field

To begin with, obtaining this certification will provide you with a top-notch qualification in the field of networking. It may assist you in standing out from other professionals in the industry and confirming your understanding to prospective employers. This validates your proficiency in resolving issues related to networks.

In essence, Cisco sets the standard against which all networking professionals are evaluated.

2. Globally Respected

Approximately one million Cisco students are currently studying in 165 countries worldwide. A Cisco certification will add a set of globally recognized and respected credentials to your resume, which can be easily translated into any language.

Earning Cisco qualifications can offer work and travel abroad opportunities, making it a suitable option for those seeking global career prospects.

3. Become Sought-After Professional

In simple terms, employers are seeking candidates who hold relevant qualifications. According to a survey, 93% of employers acknowledge that Cisco-certified employees are not just an asset to their organization. Still, they also possess more excellent knowledge than their counterparts who still need certification.

Becoming Cisco certified is becoming increasingly important for businesses and Cisco partners. Many require Cisco-certified employees, making CCNP Enterprise-qualified individuals highly sought after in the industry.

4. Makes You an Expert

Cisco certifications offer the opportunity to focus on a specific area of networking that aligns with your interests. This means you can pursue a field you are passionate about while establishing yourself as an authority in your chosen networking specialization.

There are nine distinct paths to choose from, each offering a diverse range of continuously evolving content. This means you have many options when deciding which course to take.

5. Higher Salary

In the end, obtaining a Cisco certification is the optimal approach if you desire a well-paying profession. Those with Cisco certifications earn up to 15% more than others in comparable positions.

Conclusion

Preparing for the Cisco 300-415 ENSDWI exam may seem challenging, but don’t give up. Keep striving until you pass the test and earn your CCNP Enterprise certification. It’s important to remember that worthwhile accomplishments require effort and persistence. Best of luck to you!

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