ActualTests.Cisco.640-802.Exam.Q.and.A.08.15.08-DDU (1130589), страница 31
Текст из файла (страница 31)
In order to reset the configuration revision of a switch, change theVTP domain name, and then change the name back to the original name.Reference:http://www.cisco.com/en/US/tech/ CK3 89/ CK6 89/technologies_tech_note09186a0080094c52.shtmlQUESTION 249:A simple Certkiller network is displayed in the diagram below:When PC1 sends an ARP requests for the MAC address of PC2, networkperformance slows dramatically, and the Certkiller switches detect an unusuallyhigh number of broadcast frames.
What is the most likely cause of this?A. The portfast feature is not enabled on all switch ports.B. The PCs are in two different VLANS.C. Spanning Tree Protocol is not running on the switches.D. PC2 is down and is not able to respond to the request.E. The VTP version running on the two switches do not match.F.
None of the aboveAnswer: CExplanation:As the switches CK1 and CK2 are connected with each other via two links, spanning treeActualtests.com - The Power of Knowing640-802must be enabled on both switches to avoid switching loops and broadcast storms. AnARP request is a broadcast message. If Spanning tree is not running, broadcast loops willform reducing the performance of the network.QUESTION 250:Four Certkiller switches are connected together as shown in the network below:Study the Exhibit carefully. Based on the Spanning Tree Protocol port states shown,over which path will frames flow when set from PC1 to PC2?A.
CK1 - CK3 - CK4B. CK1 - CK2 - CK4C. CK1 - CK2 - CK3 - CK4D. CK1 - CK3 - CK2 - CK4E. None of the aboveAnswer: BExplanation:As shown in the diagram, port connecting CK3 to CK4 and CK2 to CK3 arenon-designated ports. It means that spanning tree has blocked these ports temporarily so;Actualtests.com - The Power of Knowing640-802frames will not flow through these ports. The communication will be done via CK1 toCK2 to CK4 through ROOT and DESIGNATED ports.QUESTION 251:The Certkiller LAN network for one of the offices is displayed below:Assuming there is only one VLAN in this network, which switch is acting as the rootbridge?A.
Certkiller 1B. Certkiller 2C. Certkiller 3D. A root bridge is not required in this network.E. None of the aboveAnswer: CExplanation:A root switch has all ports in non-blocking mode. Based on the diagram above, Certkiller 1and Certkiller 2 contain ports that have been blocked by the STP process, so Certkiller 3must be the root bridge.QUESTION 252:Four Certkiller switches are connected as shown in the exhibit below:Actualtests.com - The Power of Knowing640-802Refer to the exhibit above. Based on the information given, which switch will beelected root bridge and why?A. Switch A, because it has the lowest MAC addressB. Switch A, because it is the most centrally located switchC.
Switch B, because it has the highest MAC addressD. Switch C, because it is the most centrally located switchE. Switch C, because it has the lowest priorityF. Switch D, because it has the highest priorityAnswer: EExplanation:To elect the root bridge in the LAN, first check the priority value. The switch having thelowest priority will win the election process. If Priority Value is the same then it checksthe MAC Address; the switch having the lowest MAC Address will become the rootbridge.
In this case, switch C has the lowest MAC Address so it becomes the root bridge.QUESTION 253:Certkiller is experiencing network delays. The network administrator discovers thata worker in a location far from the MDF has connected an old 10BASE-T switchwith redundant links to the existing network.
How could this action be responsiblefor the impaired network performance?A. Connecting a host to the old switch has created a broadcast storm.B. The 10BASE-T switch forced the entire network to be reduced to 10 Mbps operation.C. The old switch does not support VLANs, which has disabled the VLAN configurationof the entire the network.D.
The old switch does not support full-duplex operation, effectively forcing half-duplexoperation throughout the network.E. Spanning Tree Protocol has elected the old switch as the root bridge, creatinginefficient data paths through the switched network.F. None of the aboveAnswer: EExplanation:Without the Spanning Tree Protocol (STP), frames would loop for an indefinite period of time in networkswith physically redundant links. To prevent looping frames, STP blocks some ports from forwardingframes so that only one active path exists between any pair of LAN segments (collision domains).
Theresult of STP is good: Frames do not loop infinitely, which makes the LAN usable. However, the networkuses some redundant links in case of a failure, but not for balancing traffic.To avoid loops, all bridging devices, including switches, use STP. STP causes each interface on a bridgingdevice to settle into a blocking state or a forwarding state. Blocking means that the interface cannotActualtests.com - The Power of Knowing640-802forward or receive data frames.
Forwarding means that the interface can send and receive data frames. Byhaving a correct subset of the interfaces blocked, a single currently active logical path will exist betweeneach pair of LANs. STP behaves identically for a transparent bridge and a switch. So, the terms bridge,switch, and bridging device all are used interchangeably when discussing STP.Root bridge The rootbridge is the bridge withthe best bridge ID. WithSTP, the key is for all theswitches in the networkto elect a root bridge thatbecomes the focal pointin the network.
All otherdecisions in thenetwork-like which portis to be blocked andwhich port is to be put inforwarding mode-aremade from theQUESTION 254:The "show interfaces" command was issued on a Certkiller router as shown below:Assume that the router is configured with the default settings. Based on theinformation shown above, what type of router interface is this?A. EthernetB. Gigabit EthernetC. FastEthernetD. Synchronous SerialE. Asynchronous SerialAnswer: CExplanation:See the output of a serial interface shown below and compare:RouterA#show interfaces serial 0Serial0 is down, line protocol is downHardware is HD64570Internet address is 192.168.0.1/24MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,Actualtests.com - The Power of Knowing640-802reliability 255/255, txload 1/255, rxload 1/255Encapsulation HDLC, loopback not setKeepalive set (10 sec)Last input never, output never, output hang neverLast clearing of "show interface" counters neverInput queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0Queueing strategy: fifoOutput queue :0/40 (size/max)5 minute input rate 0 bits/sec, 0 packets/sec5 minute output rate 0 bits/sec, 0 packets/sec0 packets input, 0 bytes, 0 no bufferReceived 0 broadcasts, 0 runts, 0 giants, 0 throttles0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort0 packets output, 0 bytes, 0 underruns0 output errors, 0 collisions, 2 interface resets0 output buffer failures, 0 output buffers swapped out0 carrier transitionsDCD=down DSR=down DTR=up RTS=up CTS=downIn this exhibit the BW=10000Kbit and the encapsulation type is ARPA which means itcould only be a Fast Ethernet interface.QUESTION 255:The following output was displayed on a Certkiller device:Study the exhibit above.
Switch- Certkiller 1 needs to send data to host with a MACaddress of 00b0.d056.efa4. What will Switch- Certkiller 1 do with this data?A. Switch- Certkiller 1 will send an ARP request out all its ports except the port fromwhich the data originatedB.
Switch- Certkiller 1 will drop the data because it does not have an entry for the MACaddressC. Switch- Certkiller 1 will forward the data to its default gatewayD. Switch- Certkiller 1 will flood the data out all of its ports except the port from whichActualtests.com - The Power of Knowing640-802the data originatedE. None of the aboveAnswer: DExplanation:Switches work as follows:Switches learn tha MAC addresses of PC or workstation that are connected to theirswitch ports by examining the source address of frames that are received on that port.Machines may have been removed from a port ,turned off, or moved to another port onthe same switch or a different switch.This could cause confusion in frame forwardingThe MAC address entry is automatically discard or ages out after 300 secondsif there is not MAC address of destination host in MAC table, switch sends broadcastto all ports except the source to find out the destination host.In output there is no MAC address of give host so switch floods to all ports except thesource port.QUESTION 256:Some Certkiller devices are connected as shown below:The router shows the FastEthernet port as being up, and the computer on VLAN 3can ping all of the FastEthernet IP addresses on the router.Actualtests.com - The Power of Knowing640-802Computer 1 is used to console into switch CertkillerA.
From the command promptof switch Certkiller A, the switch cannot ping the computer on VLAN 3. The switchconfiguration shown in the exhibit lists only the commands that are different fromthe default configuration. What is the problem, based on the information shown?A. Computer 1 must be connected to a switch port in order to communicate with a devicelocated on VLAN 3.B. Switch Certkiller A does not have a default gateway assigned.C. The router is not routing VLAN 3 information.D. The computer on VLAN 3 is assigned an incorrect IP address.E.
![](https://s.studizba.com/z.php?f=/templates/si/i/noavatar.png&w=100&h=100&t=1"){kind=avatar}
