Category Archives: Priority Queuing

Pearson Cert Practice Test Engine and Questions on the Website – Final Preparation

Register this book to get access to the Pearson IT Certification test engine (software that displays and grades a set of exam-realistic multiple-choice questions). Using the Pearson Cert Practice Test Engine, you can either study by going through the questions in Study mode or take a simulated (timed) 300-420 CCNP Designing Cisco Enterprise Networks ENSLD… Read More »

Priority Queuing – WAN Availability and QoS

Priority queuing (PQ) is a queuing method that establishes four interface output queues that serve different priority levels: high, medium, default, and low. Unfortunately, PQ can starve other queues if too much data is in one queue because higher-priority queues must be emptied before lower-priority queues. Custom Queuing Custom queuing (CQ) uses up to 16… Read More »

SD-Access Architecture – SD-Access Design

Cisco Software-Defined Access (SD-Access) is an intent-based networking solution for the enterprise that is built on the foundation of Cisco Digital Network Architecture (DNA). The SD-Access solution provides automated end-to-end segmentation for users and devices from the edge of the network to applications. SD-Access leverages Cisco DNA Center to provide the design settings, policy definition,… Read More »

SD-Access Fabric Design Considerations for Wired and Wireless Access – SD-Access Design

When you’re designing an SD-Access solution, in addition to the typical business requirements, there are a number of key technical factors that need to be considered before you develop your final design. This list is not exhaustive but should give you some design guidance to keep in mind: Overlay Design The overlay network within the… Read More »

Large Site Design Considerations – SD-Access Design

Typically, a large site is designed with a three-tier network that consists of separate core, distribution, and access layers. These larger site networks are designed to support up to 50,000 endpoints. Multiple service exit points with dedicated data center connections, a shared services block, and Internet services are common. In a multi-fabric deployment, the headquarters… Read More »

Onboarding and Provisioning – SD-WAN Design

vEdge devices can be onboarded via two methods: Zero Touch Provisioning (ZTP) or manual configuration. ZTP does require some initial steps on Cisco’s Plug and Play (PnP) Connect portal: Step 1. Use the PnP Connect portal, which is linked to Cisco Commerce Workspace (CCW), to place an order for SD-WAN devices with PnP licenses. Step… Read More »

Onboarding Cisco IOS XE SD-WAN Routers – SD-WAN Design

Cisco IOS XE devices can be onboarded in three different ways: SD-WAN Security Cisco’s SD-WAN solution provides security for the management plane, control plane, and data plane. The control plane uses a Zero Trust model, the management plane uses role-based access control (RBAC) and access control lists (ACLs), and the data plane has integrated on-premises… Read More »

Network/Headend Redundancy – SD-WAN Design

SD-WAN provides network/headend redundancy so that in the event of loss of connectivity via the primary network headend vEdge router at the data center, the vEdge router can connect to a redundant headend vEdge router (see Figure 11-6). Figure 11-6 Network/Headend Redundancy Controller Redundancy As mentioned previously, you can increase the number of vSmart controllers… Read More »

Policies – SD-WAN Design

Policies can be configured to influence the flow of traffic in the overlay network. Policies can be control plane or data plane policies, and they can be configured centrally on the vSmart controller or locally on the vEdge routers. Centralized control policies operate on the routing and TLOC information and allow for customization of routing… Read More »

vEdge Interface Queues – SD-WAN Design

Each vEdge interface has eight queues. Of these queues, queue 0 uses LLQ. By default, control and BFD traffic use queue 0. Control and BFD traffic is marked as DSCP 48 decimal. LLQ traffic is transmitted before packets in any of the other queues. The only congestion-avoidance algorithm used for this queue is tail drop,… Read More »