Chapter 4: Switched Networks CCNA Routing and Switching

Chapter 4: Switched Networks CCNA Routing and Switching

Chapter 4: Switched Networks CCNA Routing and Switching Routing and Switching Essentials v6.0 Chapter 4 - Sections & Objectives 4.1 LAN Design Explain how switched networks support small to medium-sized businesses. Explain how data, voice, and video are converged in a switched network. Describe a switched network in a small to medium-sized business. 4.2 The Switched Environment Explain how Layer 2 switches forward data in a small to medium-sized LAN.

Explain how frames are forwarded in a switched network. Compare a collision domain to a broadcast domain. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 4.1 LAN Design 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 Converged Networks Growing Complexity of Networks Next-generation networks need to

be secure, reliable, and highly available. They must support a globalized workforce. They must be able to integrate legacy devices. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 Converged Networks Elements of a Converged Network

Converged network solutions integrate voice systems, IP phones, voice gateways, video support, and video conferencing. Primary benefit of the converged network - just one physical network to install and manage. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 Converged Networks Cisco Borderless Networks

The Cisco Borderless Network has the following features: Allows organizations to connect anyone, anywhere, anytime, on any device; securely, reliably, and seamlessly. Provides the framework to unify wired and wireless access, including policy, access control, and performance management across many different device types. Provides network services, and user and endpoint services that are all managed by an integrated management solution. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

6 Converged Networks Hierarchy in the Borderless Switched Network Borderless switched network design guidelines are based on the following principles: Hierarchical - Facilitates understanding the role of each device at every tier. Modularity - Allows seamless network expansion and integrated services. Resiliency Provides an always available network. Flexibility - Allows intelligent traffic load sharing.

The three tiers of the hierarchical model are Access, Distribution and Core layers. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 Converged Networks Access, Distribution, and Core Layers Access Layer provides network access to the user. Distribution Layer - interfaces between the access layer and the core layer. Provides functions such as:

aggregating Layer 2 broadcast domains and Layer 3 routing boundaries. providing intelligent switching, routing, and network access policy functions to access the rest of the network. Core Layer - is the network backbone. It provides fault isolation and high-speed backbone connectivity. Smaller networks that do not need a separate distribution and core layer often use a two-tier campus or collapsed core network design. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8

Switched Networks Role of Switched Networks A hierarchical switched LAN allows more flexibility, traffic management, and additional features: Quality of service Additional security Support for wireless networking and connectivity Support for new technologies. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9

Switched Networks Form Factors Stackable Configuration Fixed Configuration Considerations when selecting switches: Cost Port Density Power Reliability Port Speed Frame buffers Modular Configuration

Scalability 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 4.2 The Switched Environment 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 Frame Forwarding Switching as a General Concept in Networking and Telecommunications

A LAN switch makes decisions based on two criteria: Ingress port - where a frame enters the device Destination address A LAN switch maintains a table that it uses to determine how to forward traffic. In the diagram, If a message enters switch port 1 with a destination address of EA, then the switch forwards the traffic out port 4. Layer 2 Ethernet switches forward frames based on the destination MAC address. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

12 Frame Forwarding Video Demonstration - MAC Address Tables on Connected Switches The video explains how a switch builds its MAC address table by recording the MAC address of each device connected to each of its ports. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 Frame Forwarding

Switch Forwarding Methods 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 Frame Forwarding Store-and-Forward Switching Features of Store-and-Forward Switching: Error Checking After receiving the entire frame, the switch compares the frame-check-sequence (FCS) value in the last field against its own FCS

calculations. Only error-free frames are forwarded Automatic Buffering ingress port buffering provides the flexibility to support any mix of Ethernet speeds. Store-and-Forward is Ciscos primary LAN switching method. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 Frame Forwarding Cut-Through Switching Rapid Frame Forwarding - The switch

can make a forwarding decision as soon as it has looked up the destination MAC address. Frames with errors are forwarded. Fragment Free - modified form of cut- through switching. The switch waits for the collision window (64 bytes) to pass before forwarding the frame. Provides better error checking than cutthrough, with practically no increase in latency. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16

Switching Domains Collision Domains In hub-based Ethernet segments, network devices compete for the medium, therefore collisions will occur. Ethernet switch ports operating in full duplex eliminate collisions. Ethernet switch ports will autonegotiate full-duplex if connected to full-duplex device. If connected to a half-duplex device then the switch port will operate in half

duplex and be part of a collision domain. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17 Switching Domains Broadcast Domains One switch or multiple interconnected switches form a single broadcast domain. When a switch receives a broadcast

frame, it forwards the frame out each of its ports, except the ingress port where the broadcast frame was received. When two switches or more switches are connected together, the broadcast domain is increased because the broadcast is propagated from switch to switch. Too many broadcasts can cause network congestion. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 Switching Domains

Alleviating Network Congestion The following characteristics of switches help alleviate congestion: Establishing full-duplex links, therefore eliminating collisions. High port density Large frame buffers Port speed Fast internal switching Low per-port cost 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19

4.3 Chapter Summary 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 Conclusion Chapter 4: Switched Networks Explain how switched networks support small to medium-sized businesses. Explain how Layer 2 switches forward data in a small to medium-sized LAN. 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21

Recently Viewed Presentations

  • Sponsorship

    Sponsorship

    2018 Highway Plan Project File. Projects eligible for sponsorship. CHAF ID for each Item #, there may be multiple. NHS "Y" if >50% of the project is on a NHS route. Projects not sponsored: Of all SHIFT eligible projects in...
  • Suicide Assessment - University of Maryland, Baltimore

    Suicide Assessment - University of Maryland, Baltimore

    Suicide Statistics . Fatal Outcomes (Suicides) in 2010: 38,364 total for the year, an average of 105 per day. In 2010 , suicide was the 10th leading cause of death for all ages
  • 17.1 How Light Behaves at a Boundary - yourjedimaster.com

    17.1 How Light Behaves at a Boundary - yourjedimaster.com

    How light behaves a at boundary By Victoria Skinner 17.1 How Light Behaves at a Boundary law of reflection *If 2 parallel beams strike a mirror 2 reflected beams are also parallel *If a line is perpendicular to a mirror...
  • Forming Plurals

    Forming Plurals

    FORMING PLURALS Most nouns Nouns ending in ss, sh, ch, x tomato, potato, mango Nouns ending in consonant + y Nouns ending in f, fe Add s Add es (e.g. dishes, classes)
  • Diapositiva 1 - WordPress.com

    Diapositiva 1 - WordPress.com

    En 1955, cuando Wechsler realizó la revisión de la prueba, incrementó la dificultad progresiva entre cada reactivo, se eliminaron unos y se aumentaron otros, ya sea por su baja validez o por su ambigüedad ALTERNATIVAS APROPIADAS. Las escalas de Wechsler...
  • Diapositiva 1

    Diapositiva 1

    y causan menos del 1% de los CM. La combinación de todos ellos supone aproximadamenteel 20% del componente genético del riesgo de CM.
  • 11th Grade IBDP Meeting

    11th Grade IBDP Meeting

    IB only allows teachers to give feedback one time. Turn It In: Plagiarism online site—used as a tool to teach students to monitor for plagiarism. Students who fail to submit initial draft will not receive feedback. Students who fail to...
  • mrfitton.weebly.com

    mrfitton.weebly.com

    Torts. Two Types: Unintentional Torts - injuries caused by accident or an action not intended to cause harm (negligence) Intentional Torts - actions intended to cause injury with others