500-490 Designing Cisco Enterprise Networks (ENDESIGN) exam Questions and Answers

The three focus areas for reinventing the WAN are:

• Secure Elastic Connectivity: This refers to the ability to provide secure and flexible connectivity to any application, anywhere, and anytime. Secure elastic connectivity enables the network to adapt to the changing business needs and user demands, while maintaining security and performance. Secure elastic connectivity leverages SD-WAN technologies, such as Cloud OnRamp, SASE, and ThousandEyes, to optimize the network path, encrypt the traffic, and monitor the end-to-end visibility across the WAN12.
• Application Quality of Experience: This refers to the ability to ensure optimal and consistent user experience for any application, regardless of the network conditions. Application quality of experience uses SD-WAN technologies, such as vAnalytics, to measure and improve the application performance, availability, and reliability across the WAN3. Application quality of experience also uses intelligent policies and real-time analytics to prioritize the critical applications and steer the traffic to the best-performing path4.
• Cloud First: This refers to the ability to embrace the cloud as the primary platform for delivering applications and services to the users. Cloud first enables the network to support the multicloud strategy and accelerate the cloud adoption. Cloud first leverages SD-WAN technologies, such as Cloud OnRamp, to simplify and automate the connectivity to the public cloud, SaaS, and cloud interconnect providers4. Cloud first also enables the network to operate as a cloud-native WAN overlay, using software-defined automation and orchestration tools5.

References:

• Cisco SD-WAN Architecture Overview
• SD-WAN and SASE: The new landscape of networking
• Under the vAnalytics Hood: Enabling Total Network Visibility, Total Network Control
• SD-WAN Capabilities - The New Landscape of Networking
• Software-defined WAN (SD-WAN): the new landscape of networking

The node that enables Cisco ISE to share contextual information on a device with Cisco Stealthwatch is the pXGrid Controller. The pXGrid Controller is a component of the ISE Policy Service Node (PSN) that facilitates the exchange of contextual data between ISE and other security products, such as Stealthwatch, via the Platform Exchange Grid (pxGrid) protocol. The pXGrid Controller acts as a broker that registers, authenticates, and authorizes pxGrid clients, and allows them to publish and subscribe to topics of interest. For example, Stealthwatch can subscribe to the Session Directory topic to obtain user and device information from ISE, and use it to enrich the network flow data and provide better visibility and security analytics. Stealthwatch can also publish topics, such as Rapid Threat Containment (RTC), to allow ISE to take mitigation actions on compromised endpoints, such as quarantine or re-authentication. References:

• Cisco Identity Services Engine Administrator Guide, Release 2.4 - Manage Platform Exchange Grid Services [Cisco Identity Services Engine] - Cisco1
• Deploying Cisco Stealthwatch 7.x with Cisco ISE 2.4 using pxGrid - Cisco Community2
• Stealthwatch — Networking fun3
• pxGrid in Depth > Sharing the Context | Cisco Press4

 = A business case is an option that will help build your customers platform during the discovery phase. A business case is a document that outlines the rationale, objectives, benefits, costs, risks, and alternatives of a proposed project or solution. A business case helps to justify the investment and align the stakeholders on the value proposition of the project or solution12.

During the discovery phase, the goal is to understand the problem that needs to be solved, the user needs and context, the constraints and opportunities, and the underlying policy intent. A business case can help to achieve this goal by providing a clear and concise summary of the problem statement, the desired outcomes, the potential solutions, and the evaluation criteria34. A business case can also help to communicate the vision and scope of the project or solution to the customers and other stakeholders, and to secure their buy-in and support56.

A business case is not the same as a POV report, a detailed design, a high-level design, or a PO. A POV report is a document that summarizes the findings and recommendations from a proof of value (POV) exercise, which is a short-term trial of a solution to demonstrate its feasibility and benefits7. A detailed design is a document that specifies the technical and functional requirements, architecture, and configuration of a solution8. A high-level design is a document that provides an overview of the solution, such as the main components, interfaces, and interactions9. A PO is a purchase order, which is a document that authorizes a purchase transaction between a buyer and a seller.

References :=

• What is a business case? Definition and examples
• Business Case - Project Management Knowledge
• How the discovery phase works - Service Manual - GOV.UK
• Discovery Phase – Service Design – The Beginner’s Guide
• How to Write a Business Case ― 4 Steps to a Perfect Business Case Template
• How to Write a Business Case: 4 Steps to a Perfect Business Case Template
• What is a Proof of Value (POV)?
• What is a Detailed Design Document (DDD)?
• What is a High-Level Design Document?
• [What is a Purchase Order (PO)?]

 Cisco ISE use cases can be classified into four categories: device management, asset visibility, software-defined segmentation, and software-defined access. Each of these use cases has a different level of implementation complexity, depending on the network size, topology, security requirements, and integration with other technologies. Among these use cases, software-defined segmentation and software-defined access typically involve the highest level of implementation complexity, because they require:

• A thorough understanding of the network architecture and design principles, such as hierarchical, modular, and scalable design.
• A comprehensive assessment of the network devices, endpoints, users, applications, and policies, and their interdependencies and interactions.
• A careful planning and testing of the network segmentation and access policies, using tools such as Cisco TrustSec, Cisco DNA Center, Cisco SD-Access, and Cisco ISE .
• A smooth and secure migration from the existing network to the software-defined network, with minimal disruption and downtime.
• A continuous monitoring and optimization of the network performance, security, and compliance, using tools such as Cisco Stealthwatch, Cisco Tetration, and Cisco ISE .

References:

Cisco Identity Services Engine (ISE) Use Cases, https://www.cisco.com/c/en/us/products/security/identity-services-engine/use-cases.html : Cisco Enterprise Network Architecture and Design, https://www.cisco.com/c/en/us/solutions/design-zone/networking-design-guides/enterprise-networking-design.html : Cisco ISE Network Discovery, https://www.cisco.com/c/en/us/td/docs/security/ise/2-6/admin_guide/b_ise_admin_guide_26/b_ise_admin_guide_26_chapter_010011.html : Cisco TrustSec, https://www.cisco.com/c/en/us/solutions/enterprise-networks/trustsec/index.html : Cisco DNA Center, https://www.cisco.com/c/en/us/products/cloud-systems-management/dna-center/index.html : Cisco SD-Access, https://www.cisco.com/c/en/us/solutions/enterprise-networks/software-defined-access/index.html : Cisco ISE Software-Defined Access, https://www.cisco.com/c/en/us/td/docs/security/ise/2-6/admin_guide/b_ise_admin_guide_26/b_ise_admin_guide_26_chapter_010110.html : Cisco SD-Access Migration Guide, https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Campus/sda-migration-guide.html : Cisco Stealthwatch, https://www.cisco.com/c/en/us/products/security/stealthwatch/index.html : Cisco Tetration, https://www.cisco.com/c/en/us/products/data-center-analytics/tetration/index.html : Cisco ISE Monitoring and Troubleshooting, https://www.cisco.com/c/en/us/td/docs/security/ise/2-6/admin_guide/b_ise_admin_guide_26/b_ise_admin_guide_26_chapter_010100.html

 Cisco ISE benefits our customers by providing network access control and helping them stop and contain real-time threats. Network access control is the ability to enforce policies on who and what can access the network, based on the identity and context of users, devices, and applications. Cisco ISE allows customers to authenticate, authorize, and audit network access, as well as to segment and isolate network traffic based on security and compliance requirements. Cisco ISE also helps customers stop and contain real-time threats by leveraging intel from across the network and security ecosystem, and by automating threat response actions. Cisco ISE can integrate with various security solutions, such as Cisco Stealthwatch, Cisco Firepower, and Cisco Umbrella, to detect and mitigate attacks on the network quickly and effectively. References:

• Cisco Identity Services Engine (ISE) - Cisco1
• Cisco Identity Services Engine (ISE) - Cisco2
• Network Visibility and Segmentation (NVS) - Cisco3
• Rapid Threat Containment - Cisco4

Cisco ISE is a security policy management platform that provides secure access to network resources. Cisco ISE functions as a policy decision point and enables enterprises to ensure compliance, enhance infrastructure security, and streamline service operations1. Two of the statements that are true regarding Cisco ISE are:

• ISE can detect endpoints whose addresses have been translated via NAT: Cisco ISE can discover, profile, and monitor the endpoint devices on the network, and classify them according to their associated policies and identity groups. Cisco ISE can leverage the pxGrid framework to share the contextual information with other security tools and platforms, and enhance the network visibility and security1. Cisco ISE can also detect endpoints whose addresses have been translated via NAT by using various methods, such as passive and active discovery, NMAP scanning, DHCP snooping, and RADIUS accounting234.
• The number of logs that ISE can retain is determined by your disk space: Cisco ISE provides a logging mechanism that is used for auditing, fault management, and troubleshooting. The logging mechanism helps you to identify fault conditions in deployed services and troubleshoot issues efficiently. You can configure your Cisco ISE node to collect the logs in the local systems using a virtual loopback address5. The number of logs that ISE can retain is determined by your disk space, as well as the data purging settings that you can configure under Administration > System > Maintenance > Data Purging6. You can also configure Cisco ISE to send its logs to a remote system for greater retention history7.

The other statements are not true regarding Cisco ISE, because:

• In distributed deployments, failover from primary to secondary Policy Administration Nodes happens automatically: Cisco ISE supports high availability for the Administration persona, which provides centralized configuration and management of the distributed deployment. You can configure one primary Administration ISE node and one secondary Administration ISE node for high availability. However, the failover from primary to secondary Policy Administration Nodes does not happen automatically, unless you enable the automatic failover feature and configure a health check node to monitor the primary node’s status8. Otherwise, you have to manually promote the secondary node to become the primary node in case of a failure9.
• In two-node standalone ISE deployments, failover must be done manually: Cisco ISE supports high availability for the Policy Service persona, which provides network access, posture, guest access, client provisioning, and profiling services. You can configure multiple Policy Service Nodes (PSNs) in a node group to provide session failover and load balancing for the endpoints. In a two-node standalone ISE deployment, where each node assumes all the personas, the failover for the Policy Service persona does not need to be done manually, as long as the network access devices are configured to use both nodes for RADIUS and TACACS services10.
• ISE supports IPv6 downloadable ACLs: Cisco ISE supports downloadable ACLs (DACLs), which are configured and implemented through authorization profiles. DACLs are used to enforce granular access control policies for the endpoints based on their identity and other attributes. However, Cisco ISE does not support IPv6 downloadable ACLs, as it only supports IPv4 ACLs for RADIUS and TACACS protocols1112.

References:

1: Cisco Content Hub - Cisco ISE Features 2: Cisco ISE Profiler Service Overview 3: ISE Deployment through NAT Boundaries - Cisco Community 4: Configure ISE 3.3 Native IPSec to Secure NAD (IOS-XE) Communication - Cisco 5: Logging [Cisco Identity Services Engine] - Cisco Systems 6: ISE maximum logging time / data retention - Cisco Community 7: Logs retention on ISE - Cisco Community 8: Cisco Identity Services Engine Administrator Guide, Release 2.4 9: Setting Up Cisco ISE in a Distributed Environment 10: Cisco Content Hub - Network Deployments in Cisco ISE 11: Cisco Identity Services Engine Administrator Guide, Release 2.2 12: Solved: ISE: support for IPv6 DACL’s - Cisco Community

= Border nodes are the component of the SD-Access fabric that is responsible for communicating with networks that are external to the fabric. Border nodes serve as the gateway between the fabric domain and the network outside of the fabric. Border nodes are responsible for network virtualization inter-working and SGT propagation from the fabric to the rest of the network1. Border nodes also perform LISP Proxy Tunnel Router (PxTR) functions, which convert policy and reachability information, such as SGT and VRF information, from one domain to another2. Border nodes can connect to internal networks, such as data center or WAN, or external networks, such as internet or cloud3.

Edge nodes, control plane nodes, and intermediate nodes are not responsible for communicating with networks that are external to the fabric. Edge nodes are the access-layer switches where all of the endpoints reside. Edge nodes detect clients and register them with the control plane nodes. Edge nodes also provide an anycast L3 gateway for the connected endpoints and perform encapsulation and de-encapsulation of data traffic4. Control plane nodes are the devices that run a host tracking database to map location information. Control plane nodes receive endpoint ID map registrations from edge and/or border nodes and resolve lookup requests from edge and/or border nodes to locate destination endpoint IDs5. Intermediate nodes are the devices that provide underlay connectivity between edge nodes and border nodes. Intermediate nodes do not participate in the fabric overlay and do not have any fabric roles6.

References :=

• Role of Fabric Border Node & IS-IS protocol in Cisco SD-Access
• Software Defined Access Network Fabric Roles - Study CCNP
• Cisco SD-Access
• SD-Access Fabric Troubleshooting Guide - Cisco
• Cisco SD-Access Solution Design Guide (CVD) - Cisco
• Cisco SD-Access Solution Design Guide (CVD) - Cisco
• Cisco SD-Access Solution Design Guide (CVD) - Cisco