CCNA
What is the maximum data rate for 802.11b wireless LANs?
802.11b, also called "Wi-Fi," has a maximum data rate of 11Mbps.
Which of the following describes a MAC address? (Choose two.)
A MAC address is 6 bytes long (48 bits) and is burned into the NIC card by the manufacturer. IPX, when it was still used, used the MAC address as part of the configuration.
Acknowledgements, sequencing, and flow control are characteristic of which OSI layer?
A reliable Transport layer connection uses acknowledgments to make sure all data is transmitted and received reliably. A reliable connection is defined by a virtual circuit that uses acknowledgments, sequencing, and flow control, which are characteristics of the Transport layer (layer 4).
What is split horizon?
A split horizon will not advertise a route back to the same router it learned the route from.
What protocol is used to find the hardware address of a local device?
Address Resolution Protocol (ARP) is used to find the hardware address from a known IP address.
Which of the following are considered some reasons for LAN congestion? (Choose six.)
Although Bill Gates is a good answer for me, the answers are: not enough bandwidth, too many users, broadcast storms, multicasting, adding hubs for connectivity to the network, and a large amount of ARP or IPX traffic.
Which fields are contained within an IEEE Ethernet frame header? (Choose two.)
An Ethernet frame has source and destination MAC addresses, an Ether-Type field to identify the Network layer protocol, the data, and the FCS field that holds the result of the CRC.
What is route poisoning?
Another way to avoid problems caused by inconsistent updates and to stop network loops is route poisoning. When a network goes down, the distance-vector routing protocol initiates route poisoning by advertising the network with a metric of 16, or unreachable (sometimes referred to as infinite).
What are two purposes for segmentation with a bridge?
Bridges break up collision domains, which allows more bandwidth for users.
Which of the following services use UDP? (Choose three.)
DHCP, SNMP and TFTP use UDP. SMTP, FTP, and HTTP use TCP.
A network administrator needs to configure a router with a distance vector protocol that allows classless routing. Which of the following satisfies those requirements?
Distance vector? In this question, we're calling EIGRP just plain old distance vector. EIGRP is an "advanced" distance vector routing protocol, sometimes called a hybrid routing protocol because it uses the characteristics of both distance vector and link state routing protocols.
You want to implement a network medium that is not susceptible to EMI. Which type of cabling should you use?
Fiber optic cable provides a more secure, long-distance cable that is not susceptible to EMI interference at high speeds.
Which of the following types of connections can use full duplex? (Choose three.)
Hubs cannot run full-duplex Ethernet. Full duplex must be used on a point-to-point connection between two devices capable of running full duplex. Switches and hosts can run full duplex between each other.
IGRP uses which of the following as default parameters for finding the best path to a remote network? (Choose two.)
IGRP uses bandwidth and delay of the line, by default, to determine the best path to a remote network. Delay of the line can sometimes be called the cumulative interface delay.
What is the problem with an interface if you type show interface serial 0 and receive the following message?
If an interface is shut down, the show interface command will show the interface as administratively shut down. (It is possible that no cable is attached, but you can't tell that from this message.)
If you delete the contents of NVRAM and reboot the router, what mode will you be in?
If you delete the startup-config and reload the router, the router will automatically enter setup mode. You can also type setup from privileged mode at any time.
If you type a command and receive the error % incomplete command from a switch CLI, what would you do to get help?
If you receive the % incomplete command error, just press your Up arrow key, then a question mark to see what the next available parameter is in the command string.
Which command will copy the IOS to a backup host on your network?
If you save a configuration and reload the router and it comes up either in setup mode or as a blank configuration, chances are you have the configuration register setting incorrect.
You want to use full-duplex Ethernet instead of half duplex. Which two of the following will be benefits on your network?
No collision on a point-to-point full-duplex Ethernet segment should occur, and fullduplex Ethernet should be faster then half-duplex Ethernet.
How does a host on an Ethernet LAN know when to transmit after a collision has occurred?
Once transmitting stations on an Ethernet segment hear a collision, they send an extended jam signal to ensure that all stations recognize the collision. After the jamming is complete, each sender waits a predetermined amount of time, plus a random time. After both timers expire, they are free to transmit.
PDUs at the Network layer of the OSI are called what?
Packets
Which of the following describe router functions? (Choose four.)
Routers provide packet switching, packet filtering, internetwork communication, and path selection.
Which of the following are reasons for breaking up a network into two segments with a router? (Choose two.)
Routers, by default, break up broadcast domains, which means that broadcasts sent on one network would not be forwarded to another network by the router.
What technology is used by Catalyst switches to resolve topology loops and ensure that data flows properly through a single network path?
Spanning Tree Protocol (STP) will make sure that no network loops occur at layer 2.
Which of the following statements is true?
Switches break up collision domains, and routers break up broadcast domains.
What does a switch do when a frame is received on an interface and the destination hardware address is unknown or not in the filter table?
Switches flood all frames that have an unknown destination address. If a device answers the frame, the switch will update the MAC address table to reflect the location of the device.
Segmentation of a data stream happens at which layer of the OSI model?
The Transport layer receives large data streams from the upper layers and breaks these up into smaller pieces called segments.
Which of the following are types of flow control?
The common types of flow control are buffering, windowing, and congestion avoidance.
The configuration register setting of 0x2102 provides what function to a router?
The default configuration setting of 0x2102 tells the router to look in NVRAM for the boot sequence.
When data is encapsulated, which is the correct order?
The encapsulation method is: data, segment, packet, frame, bit.
You have the following MAC address: C9-3F-32-B4-DC-19. What is the OUI portion in binary?
The first three bytes of a hardware (MAC) address are considered the OUI portion and identify the manufacturer of the card. This code, which is assigned by the IEEE, is called the organizationally unique identifier (OUI). The first three bytes are C9-3F-32, which is 11001001- 00111111-00110010 in binary
Why does the data communication industry use the layered OSI reference model? (Choose two.)
The main advantage of a layered model is that it can allow application developers to change aspects of a program in just one layer of the layer model's specifications. Advantages of using the OSI layered model include, but are not limited to, the following: It divides the network communication process into smaller and simpler components, thus aiding component development, design, and troubleshooting; allows multiple-vendor development through standardization of network components; encourages industry standardization by defining what functions occur at each layer of the model; allows various types of network hardware and software to communicate; and prevents changes in one layer from affecting other layers, so it does not hamper development.
Which layer of the OSI provides translation of data?
The only layer of the OSI model that can change data is the Presentation layer.
Which command will show you whether a DTE or a DCE cable is plugged into serial 0?
The show controllers serial 0 command will show you whether either a DTE or DCE cable is connected to the interface.
Which command displays the configuration register setting?
The show version command provides you with the current configuration register setting.
If you wanted administrators to see a message when logging into the router, which command would you use?
The typical banner is a message of the day (MOTD) and is set by using the global configuration mode command banner motd.
What mask would you assign to the network ID of 172.16.0.0 if you needed about 100 subnets with about 500 hosts each?
This one takes some thought. 255.255.255.0 would give you 256 subnets, each with 254 hosts—doesn't work for this question. 255.255.254.0 would provide 128 subnets, each with 510 hosts; the second option looks good. 255.255.252.0 is 64 subnets, each with 1022 hosts. So 255.255.254.0 is the best answer.
Which command would you use to apply an access list to a router interface?
To apply an access list, the proper command is: ip access-group 101 in.
What command do you type to save the configuration stored in RAM to NVRAM?
To copy the running-config to NVRAM so that it will be used if the router is restarted, use the copy running-config startup-config (copy run start, for short) command.
Which of the following commands will reload the router?
To reload the router, use the command reload from privileged mode.
Which of the following are unique characteristics of half-duplex Ethernet when compared to full-duplex Ethernet?
Unlike full duplex, half-duplex Ethernet operates in a shared collision domain, and it has a lower effective throughput then full duplex.
You type debug ip rip on your router console and see that 172.16.10.0 is being advertised to you with a metric of 16. What does this mean?
You cannot have 16 hops on a RIP network by default. If you receive a route advertised with a metric of 16, this means it is inaccessible.