en switch v6 ch01-pbr

© 2007 – 2010, Cisco Systems, Inc. All rights reserved. Cisco Public Course v6 Chapter #

1

Chapter 1: Analyzing The Cisco Enterprise Campus Architecture

CCNP SWITCH: Implementing IP Switching

Chapter # 2 © 2007 – 2010, Cisco Systems, Inc. All rights reserved. Cisco Public

Chapter 1 Objectives

 Describe common campus design options and how design choices affect implementation and support of a campus LAN.

 Describe the access, distribution, and core layers.  Describe small, medium, and large campus network

designs.  Describe the prepare, plan, design, implement, operate,

optimize (PPDIOO) methodology.  Describe the network lifecycle approach to campus design.


Introduction to Enterprise Campus Network Design


Enterprise Network

 Core (Backbone)  Campus  Data Center  Branch  WAN   Internet Edge


Regulatory Standards (U.S.)

 There may be several legal regulations that have an impact on a network’s design.

 US regulations on networks include: •  Health Insurance Portability and Accountability Act (HIPAA) •  Sarbanes-Oxley Act •  “Records to Be Preserved by Certain Exchange Members, Brokers

and Dealers”: Securities and Exchange Commission (SEC) Rule 17a-4


Campus Designs

 Modular - easily supports growth and change. Scaling the network is eased by adding new modules in lieu of complete redesigns.

 Resilient - proper high-availability (HA) characteristics result in near-100% uptime.

 Flexible - change in business is a guarantee for any enterprise. These changes drive campus network requirements to adapt quickly.


Multilayer Switches in Campus Networks

  Hardware-based routing using Application-Specific Integrated Circuits (ASICs)

  RIP, OSPF, and EIGRP are supported

  Layer 3 switching speeds approximate that of Layer 2 switches

  Layer 4 and Layer 7 switching supported on some switches

  Future: Pure Layer 3 environment leveraging inexpensive L3 access layer switches


Cisco Switches

 Catalyst 6500 Family – used in campus, data center, and core as well as WAN and branch •  Up to 13 slots and 16 10-Gigabit Ethernet interfaces •  Redundant power supplies, fans, and supervisor engines •  Runs Cisco IOS

 Catalyst 4500 Family – used in distribution layer and in collapsed core environments •  Up to 10 slots and several 10-Gigabit Ethernet interfaces •  Runs Cisco IOS

 Catalyst 3560 and 3750 Families – used in fixed-port scenarios at the access and distribution layers

 Nexus 2000, 5000, and 7000 Families – NX-OS based modular data center switches


Multilayer Switching Miscellany

  ASIC-based (hardware) switching is supported even with QoS and ACLs, depending on the platform; 6500 switches support hardware-based switching with much larger ACLs than 3560 switches.

  ASICs on Catalyst switches work in tandem with ternary content addressable memory (TCAM) and packet-matching algorithms for high-speed switching.

  Catalyst 6500 switches with a Supervisor Engine 720 and a Multilayer Switch Feature Card (MSFC3) must software-switch all packets requiring Network Address Translation.

  Unlike CPUs, ASICs scale in switching architectures. ASICs integrate onto individual line modules of Catalyst switches to hardware-switch packets in a distributed manner.


Traffic Types

  Network Management – BPDU, CDP, SNMP, RMON, SSH traffic (for example); low bandwidth

  IP Telephony – Signaling traffic and encapsulated voice traffic; low bandwidth

  IP Multicast – IP/TV and market data applications; intensive configuration requirements; very high bandwidth

  Normal Data – File and print services, email, Internet browsing, database access, shared network applications; low to medium bandwidth

  Scavenger Class – All traffic with protocols or patterns that exceed normal data flows; less than best-effort traffic, such as peer-to-peer traffic (instant messaging, file sharing, IP phone calls, video conferencing); medium to high bandwidth


Client-Server Applications

 Mail servers  File servers  Database servers  Access to applications is

fast, reliable, and secure


Client-Enterprise Edge Applications

 Servers on the enterprise edge, exchanging data between an organization and its public servers

 Examples: external mail servers, e-commerce servers, and public web servers

 Security and high availability are paramount


Service-Oriented Network Architecture (SONA)

  Application Layer – business and collaboration applications; meet business requirements leveraging interactive services layer.

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

  Networked Infrastructure Layer – where all IT resources interconnect.


Borderless Networks

 Enterprise architecture launched by Cisco in October 2009.  Model enables businesses to transcend borders, access

resources anywhere, embrace business productivity, and lower business and IT costs.

 Focuses more on growing enterprises into global companies.

 Technical architecture based on three principles: •  Decoupling hardware from software •  Unifying computation, storage, and network •  Policy throughout the unified system

 Provides a platform for business innovation.  Serves as the foundation for rich-media communications.


Enterprise Campus Design


Building Access, Building Distribution, and Building Core Layers

  Building Core Layer: high-speed campus backbone designed to switch packets as fast as possible; provides high availability and adapts quickly to changes.

  Building Distribution Layer: aggregate wiring closets and use switches to segment workgroups and isolate network problems.

  Building Access Layer: grant user access to network devices.


Core Layer

 Aggregates distribution layer switches.   Implements scalable protocols and technologies and load

balancing.  High-speed layer 3 switching using 10-Gigabit Ethernet.  Uses redundant L3 links.


Distribution Layer   High availability, fast path recovery, load balancing, QoS, and security   Route summarization and packet manipulation   Redistribution point between routing domains   Packet filtering and policy routing to implement policy-based connectivity   Terminate VLANs   First Hop Redundancy Protocol


Access Layer

  High availability – supported by many hardware and software features, such as redundant power supplies and First Hop Redundancy Protocols (FHRP).

  Convergence – provides inline Power over Ethernet (PoE) to support IP telephony and wireless access points.

  Security – includes port security, DHCP snooping, Dynamic ARP inspection, IP source guard.


Small Campus Network

  <200 end devices  Collapsed core  Catalyst 3560 and 2960G switches for access layer  Cisco 1900 and 2900 routers to interconnect branch/WAN


Medium Campus Network

  200-1000 end devices  Redundant multilayer switches at distribution layer  Catalyst 4500 or 6500 switches


Large Campus Network

  >2000 end users  Stricter adherence to core, distribution, access delineation  Catalyst 6500 switches in core and distribution layers  Nexus 7000 switches in data centers  Division of labor amongst network engineers


Data Center Infrastructure

  Core layer – high-speed packet switching backplane   Aggregation layer – service module integration, default gateway

redundancy, security, load balancing, content switching, firewall, SSL offload, intrusion detection, network analysis

  Access layer – connects servers to network


PPDIOO Lifecycle Approach to Network Design and Implementation


PPDIOO Phases

 Prepare – establish organizational requirements.  Plan – identify initial network requirements.  Design – comprehensive, based on planning outcomes.   Implement – build network according to design.  Operate – maintain network health.  Optimize – proactive management of network.


Lifecycle Approach

  Lowering the total cost of network ownership

  Increasing network availability

  Improving business agility  Speeding access to

applications and services   Identifying and validating

technology requirements  Planning for infrastructure

changes and resource requirements

 Developing a sound network design aligned with technical requirements and business goals

 Accelerating successful implementation

  Improving the efficiency of your network and of the staff supporting it

 Reducing operating expenses by improving the efficiency of operational processes and tools


Lifecycle Approach (1)

 Benefits: •  Lowering the total cost of network ownership •  Increasing network availability •  Improving business agility •  Speeding access to applications and services

  Lower costs: •  Identify and validate technology requirements •  Plan for infrastructure changes and resource requirements •  Develop a sound network design aligned with technical requirements

and business goals •  Accelerate successful implementation •  Improve the efficiency of your network and of the staff supporting it •  Reduce operating expenses by improving the efficiency of operational

processes and tools


Lifecycle Approach (2)   Improve high availability:

•  Assessing the network’s security state and its capability to support the proposed de-sign •  Specifying the correct set of hardware and software releases, and keeping them opera-tional and current •  Producing a sound operations design and validating network operations •  Staging and testing the proposed system before deployment •  Improving staff skills •  Proactively monitoring the system and assessing availability trends and alerts

  Gain business agility: •  Establishing business requirements and technology strategies •  Readying sites to support the system that you want to implement •  Integrating technical requirements and business goals into a detailed design and demonstrating •  that the network is functioning as specified •  Expertly installing, configuring, and integrating system components •  Continually enhancing performance

  Accelerate access to network applications and services: •  Assessing and improving operational preparedness to support current and planned network technologies

and services •  Improving service-delivery efficiency and effectiveness by increasing availability, resource capacity, and

performance •  Improving the availability, reliability, and stability of the network and the applications running on it •  Managing and resolving problems affecting your system and keeping software applications current


Planning a Network Implementation

  Implementation Components: •  Description of the step •  Reference to design documents •  Detailed implementation guidelines •  Detailed roll-back guidelines in case of failure •  Estimated time needed for implementation

 Summary Implementation Plan – overview of implementation plan

 Detailed Implementation Plan – describes exact steps necessary to complete the implementation phase, including steps to verify and check the work of the network engineers implementing the plan


Chapter 1 Summary

 Evolutionary changes are occurring within the campus network.

 Evolution requires careful planning and deployments based on hierarchical designs.

 As the network evolves, new capabilities are added, usually driven by application data flows.

  Implementing the increasingly complex set of business-driven capabilities and services in the campus architecture is challenging if done in a piecemeal fashion.

 Any successful architecture must be based on a foundation of solid design theory and principles. The adoption of an integrated approach based on solid systems design principles is a key to success.


Resources

 www.cisco.com/en/US/products

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