ccna 200-301 network simulator ns2 download

ccna 200-301 network simulator ns2 download.Destination MAC source MAC destination hall source IP data frame end01-00-5E-00-00-09 0Q-1B-24-7D-25-05 224.0.0.9 192.1.1.2 Data FCSFigure 3-2-5 Multicast frames4. Duplex ModesThere are two duplex modes on Ethernet: Half-duplex and Full Duplex.(1) Half-duplexHalf-duplex communication can only be a one-way data stream, and does not send and receive data at the same time. This is similar to a walkie-talkie, where you can't listen when you're talking, and you can't talk when you're listening; listening and talking can't happen at the same time. If two devices send data at the same time, there is a collision. Therefore, half-duplex communication uses CSMA/CD,to help reduce potential collisions and post-collision processing. Half-duplex communication has poor performance as the data stream can only be transmitted in one direction at a moment in time. Half-duplex connections are typically on older hardware devices, such as hubs, as shown in Figure 3-2-6.(2) Full DuplexIn full-duplex communication, the data flow is bidirectional, and data can be sent and received simultaneously at the same time. Bidirectional transmission can improve performance and reduce the waiting time of transmission. Nowadays, Ethernet, Fast Ethernet, and Gigabit Ethernet NICs support full duplex. Switches also support full duplex. With devices connected at both ends of the cable supporting full duplex, the line's conflict detection feature is disabled. The line can transmit and receive simultaneously at the same speed, and the throughput can be up to twice the bandwidth of the link. The devices in Figure 3-2-7 can all operate in full-duplex mode. 74 Testament Chapter 3 Ethernet *| 03 ^=1 m bird-dan Figure 3-2-6 Half Duplex Mode Figure 3-2.7 Full Duplex Mode Proper 3.3 Selected Problems* 1. which statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet? A. Full-duplex Ethernet consists of a shared cable segment. B. Full-duplexEthernetusesaloopbackcircuittodetectcollisions.Half-duplexEthernetusesajamsignal. C. Full-duplex Ethernet can provide higher throughput than can half-duplex Ethernet of the same bandwidth. D. Full-duplexEthernetusestwowirestosendandreceive. half-duplexEthernetusesonewiretosendand receive. 2. a network interface port has collision detection and carrier sensing enabled on a shared twistedpairnetwork. fromthis statement, Whatisknownaboutthenetwork interfaceport? A. Thisisa10Mb/sswitchport. B. Thisisa100Mb/sswitchport. C. ThisisanEthernetportoperatingathalfduplex. D. ThisisanEthernetportoperatingatfullduplex. E. ThisisaportonanetworkinterfacecardinaPC. S.4 Answers to Questions*. 1. ft?: c QuestionQ: Which statement describes full-duplex Ethernet correctly compared to half-duplex Ethernet? Difference between full duplex and half duplex: Full duplex is the ability to both receive and send at the same time, while half duplex is the inability to send when receiving and receive when sending. So full duplex makes more efficient use of bandwidth, and for the same amount of bandwidth, full duplex provides higher throughput than half duplex. Option A says that full-duplex Ethernet is a shared link and half-duplex Ethernet is a point-to-point link, which is the opposite; Option B says that full-duplex Ethernet uses loopback circuits to detect conflicts and half-duplex Ethernet uses jam (blocking) signals. There is no conflict in full-duplex, and half-duplex lets all devices know that a conflict has occurred by sending a jam signal; option C says that full-duplex Ethernet can provide higher throughput than half-duplex Ethernet for the same bandwidth, and this option is correct: option D says that full-duplex uses two wires to send and receive, and half-duplex uses one wire to send and receive. Half-duplex uses a pair of electrical 75, CCNA Study and Lab Guide cables, not one, and digital signals are transmitted in both directions on the line. Full-duplex Ethernet uses two pairs (not two) of cable wires, with a point-to-point connection between the sender and receiver of the sending device. 2. solution: question C asks: a network interface has conflict detection and carrier listening on a shared twisted-pair network. what can be learned about this network interface as a connection interface? An interface has conflict detection and carrier listening, and is on a twisted-pair network, so it can be assumed that the interface is an Ethernet interface and operates in half-duplex mode. U76 Cisco Routers** This chapter introduces the hardware and software of the router, mainly including: the use of Cisco PacketTracer emulator, building CCNA labs with Dynamips", basic router hardware, basic software, router boot process, introduction to Cisco's command line interface, basic configuration of the router, use of CDP protocol, etc. Use of CDP protocol, etc.