Implementing Cisco Switched Networks Chapter 1 Review

This is my review and notes of Chapter 1 of “Implementing Cisco Switched Networks Foundation Learning Guide”.


Chapter 1

Chapter 1 was incredibly boring to read. As per the covered summary below, the chapter was attempting to get the reader in the mind set of different models Cisco has created that can be used as a guideline when creating a network, whether large or medium, and in either a campus or enterprise network.

In terms of the CCNP exam, probably need to know:
– The 3 campus design best practices
– Be able to successfully identify where different features belong in a network using the Hierarchical Network design mode.
– Know the 3 different layers of SONA
– Be able to successfully identify what happens at each step of the PPDIOO model.

– Different models of Cisco switches e.g. Catalyst, Nexus
– Campus Design best practices
– Hierarchical Network Design Model
– SONA (Serivce-Oriented Network Architecture
– PPDIOO (Prepare Plan Design Implement Operate Optimise)

Campus Design best practises
Basically summed up as create a network that is:
– Modular (like building blocks and scales well)
– Resilient (HA characteristics with uptime nearly 100%)
– Flexibility (Businesses are constatntly changing. Able to adapt to new business structures etc).

Hierarchical Network Design Model

Core Layer
– High Speed
– High Availability
– Adapt to changes quickly

– Basically aggregates all the distribution layer switches together with the remainder of the enterprise network.
– Provides aggregation points with redundancy through fast convergence and HA.
– Designed to scale as the distribtuion and consequently the access layer scale with future growth.

Distribution Layer
– Segment parts of the network and isolate network problems in a campus environment
– Aggregate WAN connections at the edge
– Provide a level of security
– Often acts as a service and control boundry between access and core layers

– Availability, load balancing, QoS
– HA through dual paths to Core and Access
– Provides default GW redundancy via HSRP/GLBP/VRRP
– Connects network resources to the access layer, and implements policies for QoS, Security, traffic loading, and routing.

Access Layer
– Edge devices
– Application of security, access control, filters, management etc.

– Access to default gateway redundancy (so dual links to distribution layer switches with e.g. HSRP)
– Converged – So PoE switch with IP Phones and WLAN devices attached.
– Security through: Port Security, DHCP Snooping, Dynamic ARP Inspection, IP SRC Guard.

SONA (Service-Oriented Network Architechture)

Below is my notes from when reading the book. To be honest it all just sounds like a bunch of buzz words and personally don’t feel it was explained very well. Haven’t looked any further into it.

Application Layer
– E.g. Business Apps
– Layer objective is to meet business requirements and achieve efficencies by leveraging the interactive services layer.

Interactive Services Layer
– Enables efficient allocation of resources to applications and business processes delivered through the networked infrastructure

Network Infrastructure Layer
– Where all IT resources (servers/SANs etc) are interconnected across a converged network foundation.
– Represents how resources exist in different places in the network, e.g. branch, data center, WAN etc.

PPDIOO ( Prepare Plan Design Implement Operate Optimise)

– Establishing organisational requirements
– Developing Network Strategy
– High-level conceptal Network Architechture
– Identifying HW and Costs

– Initial network requirements based on goals, facilities, user needs etc.
– Assessing current network and ensuring it will work with what is being proposed

– Well throught out detailed design that meets current business and techical requirements and incorporates specifications to support availability, reliability, security, scalability, and performance.
– Design is basis for implementation.

– Network is built to design specs, with goal of integrating devices without disrupting existing network.

– Final test of the appropriateness of the design
– Involves maintaining network health through day to day operation.

– Proactive management of the network
– Goal of this is to identify and resolve issues before they affect the organisation.
– Reactive fault detection and correction (Troubleshooting) is needed when proactive management can not predict and mitigate failures.