CẤU TRÚC MẠNG LAN (PHÂN 2) pdf

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 [...]... frames For other switches on the LAN to get broadcasted frames, broadcast frames must be 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... 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 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... 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 user Without segmentation, a LAN quickly becomes clogged with traffic and collisions • The most common causes of network congestion: – Increasingly powerful computer and network... Layer 2 fields in a frame in order to interpret layer 3 addressing information The extra processing time causes latency – Balance the use of higher layer devices to reduce network latency with the need to prevent contention from broadcast traffic or the high collision rates 25 LAN Design Considerations Removing Bottlenecks Activity 2.1.3.2 26 Forwarding Frames using a Switch 27 Switch Forwarding Methods . 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. 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. 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 of