Chapter 2: Basic Switch Concepts and Configuration ppt

CCNA – Semester 3 Chapter 2: Basic Switch Concepts and Configuration CCNA Exploration 4.0 2 Objectives • Summarize the operation of Ethernet as defined for 100/1000 Mbps LANs in the IEEE 802.3 standard. • Explain the functions that enable a switch to forward Ethernet frames in a LAN. • Configure a switch for operation in a network designed to support voice, video, and data transmissions. • Configure basic security on a switch that will operate in a network designed to support voice, video, and data transmissions. 3 Introduction to Ethernet/802.3 LANs 4 4 Media Access Control in Ethernet 5 5 CSMA/CD 6 6 CSMA/CD 7 7 CSMA/CD 8 8 CSMA/CD 9 Ethernet Communications Ethernet Communications: – Unicast – Broadcast – Multicast 10 Ethernet Communications • Ethernet Frame: • Ethernet Address [...]... releases between Cisco IOS Release 12.1(14)EA1 and 12.2(18)SE, the auto-MDIX feature is disabled by default 12 MAC Addressing and Switch MAC Address Tables 13 MAC Addressing and Switch MAC Address Tables 14 MAC Addressing and Switch MAC Address Tables 15 MAC Addressing and Switch MAC Address Tables 16 MAC Addressing and Switch MAC Address Tables 17 MAC Addressing and Switch MAC Address Tables 18 Design Considerations... Activity 2.1.3.2 26 Forwarding Frames using a Switch 27 Switch Forwarding Methods • Store -and- forward – The entire frame is received before any forwarding takes place • Cut-through – The frame is forwarded through the switch before the entire frame is received 28 Switch Forwarding Methods There are two variants of cut-through switching: • Fast-forward – switching immediately forwards a packet after... becomes clogged with traffic and collisions • The most common causes of network congestion: – Increasingly powerful computer and network technologies – Increasing volume of network traffic – High-bandwidth applications 22 Design Considerations for Ethernet/802.3 Networks LAN Segmentation • LANs are segmented into a number of smaller collision and broadcast domains using routers and switches Previously, bridges... Fragment-free switching filters out collision fragments ( < 64 bytes ) before forwarding begins 29 Symmetric and Asymmetric Switching 30 Memory buffering • In port-based memory buffering frames are stored in queues that are linked to specific incoming ports • Shared memory buffering deposits all frames into a common memory buffer which all the ports on the switch share 31 Layer 2 and Layer 3 Switching... Networks • • Bandwidth and Throughput – A major disadvantage of Ethernet 802.3 networks is collisions Collision domains: 19 Design Considerations for Ethernet/802.3 Networks Broadcast Domains: • Although switches filter most frames based on MAC addresses, they do not filter broadcast frames For other switches on the LAN to get broadcasted frames, broadcast frames must be forwarded by switches A collection... forwarded by switches A collection of interconnected switches forms a single broadcast domain Only a Layer 3 entity, such as a router, or a virtual LAN (VLAN), can stop a Layer 2 broadcast domain Routers and VLANs are used to segment both collision and broadcast domains The use of VLANs to segment broadcast domains will be discussed in the next chapter 20 Design Considerations for Ethernet/802.3 Networks... incoming ports • Shared memory buffering deposits all frames into a common memory buffer which all the ports on the switch share 31 Layer 2 and Layer 3 Switching 32 Layer 3 Switch and Router Comparison Activity 2.2.4.3 33 Switch Management Configuration 34 Navigating CLI Modes 35 Navigating CLI Modes 36 ...Duplex Settings 11 Switch Port Settings • • The Cisco Catalyst switches have three settings: – The auto option sets autonegotiation of duplex mode With autonegotiation enabled, the two ports communicate to decide the best mode of operation – The full option sets full-duplex mode – The half option sets half-duplex mode Auto-MDIX • The auto-MDIX feature is enabled by default on switches running Cisco... on the wire and the time the receiving NIC interpret these pulses • The actual propagation delay as the signal takes time to travel along the cable • Latency is added according to which networking devices 21 Design Considerations for Ethernet/802.3 Networks Network Congestion • The primary reason for segmenting a LAN into smaller parts is to isolate traffic and to achieve better use of bandwidth per... Previously, bridges were used, but this type of network equipment is rarely seen in a modern switched LAN 23 Design Considerations for Ethernet/802.3 Networks LAN Segmentation 24 LAN Design Considerations Controlling Network Latency • Consider the latency caused by each device on the network – A core level switch supporting 48 ports, running at 1000 Mb/s full duplex requires 96 Gb/s internal throughput . 3 Chapter 2: Basic Switch Concepts and Configuration CCNA Exploration 4.0 2 Objectives • Summarize the operation of Ethernet as defined for 100/1000 Mbps LANs in the IEEE 802.3 standard 13 MAC Addressing and Switch MAC Address Tables 14 MAC Addressing and Switch MAC Address Tables 15 MAC Addressing and Switch MAC Address Tables 16 MAC Addressing and Switch MAC Address. 17 MAC Addressing and Switch MAC Address Tables 18 MAC Addressing and Switch MAC Address Tables 19 Design Considerations for Ethernet/802.3 Networks • Bandwidth and Throughput – A