QA

Q&A

The questions and scenarios in this book are more difficult than what you should experience on the actual exam. The questions do not attempt to cover more breadth or depth than the exam; however, they are designed to make sure that you know the answer. Rather than allowing you to derive the answers from clues hidden inside the questions themselves, the questions challenge your understanding and recall of the subject. Hopefully, these questions will help limit the number of exam questions on which you narrow your choices to two options and then guess.

You can find the answers to these questions in Appendix A.

1.	Put the following Ethernet standards in order of increasing bandwidth: 802.3z 802.3ae 802.3 802.3u
2.	What benefits does switched Ethernet have over shared Ethernet?
3.	When a 10/100 Ethernet link is autonegotiating, which will be chosen if both stations can support the same capabilities10BASE-T full duplex, 100BASE-TX half duplex, or 100BASE-TX full duplex?
4.	How many pairs of copper wires does a 1000BASE-T connection need?
5.	A switch port is being configured as shown here. What command is needed next to set the port to full-duplex mode? Switch(config)# interface fastethernet 0/13 Switch(config-if)#
6.	If a full-duplex Gigabit Ethernet connection offers 2 Gbps throughput, can a single host send data at 2 Gbps?
7.	Which GBIC would you use for a connection over multimode fiber (MMF)?
8.	A Category 5 cable having only pins 1,2 and 3,6 has been installed and used for a Fast Ethernet link. Can this same cable be used for a migration to Gigabit Ethernet using 1000BASE-T GBICs, assuming that the length is less than 100 m?
9.	A Catalyst 3560 switch port has been configured for 100 Mbps full-duplex mode, but a link cannot be established. What are some commands that you could use to investigate and correct the problem?
10.	The 10-Gigabit Ethernet is backward-compatible with other forms of Ethernet at Layer _____ but not at Layer _____.
11.	What one switch command will select Fast Ethernet interfaces 4/1 through 48 for a common configuration?
12.	What is the purpose of a GBIC?
13.	Suppose you need to apply several different common configurations to Fast Ethernet interfaces 3/1 through 12, 3/34, 3/48, and 5/14 through 48. What commands are needed to create an interface macro to accomplish this, and what command would apply the macro?
14.	If a switch port is configured with the speed 100 and duplex full commands, what will happen if the PC connected to it is set for autonegotiated speed and duplex? Now, reverse the roles. (The switch will autonegotiate, but the PC won't.) What will happen?
15.	By default, what will a switch do if one of its ports has a serious error condition, and how can you tell when this has happened?
16.	What port speeds can you assign to a UTP Gigabit Ethernet switch port? Consider both 1000BASE-T GBIC and native RJ-45 copper switch module ports.
17.	What command can you use to make sure that no switch ports automatically are shut down in an errdisable state for any reason?
18.	Suppose you commonly find that switch ports are being shut down in errdisable because users are making their connections go up and down too often. Thinking that this might be the result of odd PC behavior, you would like to visit each user to troubleshoot the problem; however, this is a minor error and you don't want to inconvenience the end users too much. What commands can you use to have the switch automatically re-enable the ports after 10 minutes? Make sure a flapping link will be recovered automatically in this time frame.
19.	Look at the following show interfaces output. Does the high number of collisions indicate a problem? Why or why not? FastEthernet0/6 is up, line protocol is up Hardware is Fast Ethernet, address is 000a.f4d2.5506 (bia 000a.f4d2.5506) Description: Front Office PC MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Half-duplex, 10Mb/s input flow-control is off, output flow-control is off ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue :0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1321140 packets input, 227738894 bytes, 0 no buffer Received 13786 broadcasts, 0 runts, 0 giants, 0 throttles 1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 42 multicast, 0 pause input 0 input packets with dribble condition detected 87798820 packets output, 2662785561 bytes, 1316 underruns 6 output errors, 406870 collisions, 3 interface resets 0 babbles, 0 late collision, 19458 deferred 0 lost carrier, 0 no carrier, 0 PAUSE output 1316 output buffer failures, 0 output buffers swapped out