Final Exam

Subnet 192.168.1.32/27 will have a valid host range from 192.168.1.33 - 192.168.1.62 with the broadcast address as 192.168.1.63 Subnet 192.168.1.64/27 will have a valid host range from 192.168.1.65 - 192.168.1.94 with the broadcast address as 192.168.1.95 Subnet 192.168.1.96/27 will have a valid host range from 192.168.1.97 - 192.168.1.126 with the broadcast address as 192.168.1.127

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What are two characteristics of a scalable network?

1 grows in size without impacting existing users 2 suitable for modular devices that allow for expansion

A small satellite office has been given the overall network number of 192.168.99.0/24 and the network technician can subdivide the network addresses as needed. The office needs network access for both wired and wireless devices. However, because of the security consideration, these two networks should be separate. The wired network will have 20 devices. The wireless network has a potential connection of 45 devices. Which addressing scheme would be most efficient for these two networks?

192.168.99.0/26 192.168.99.64/27 Always calculate the biggest number of host devices first. To accommodate 45 devices, 6 host bits must be left because 26 = 64 (but two addresses cannot be used). The network number for the 45-device network is 192.168.99.0/26. The broadcast address is 192.168.99.63. Keep in mind that addresses 192.168.99.1 through 192.168.99.62 are for devices. The next network number is 192.168.99.64 for the 20-device wired network. To accommodate 20 devices, 5 bits must be left for host bits because 25 = 32 (but two addresses cannot be used. The mask would be /27 or 255.255.255.224.

Refer to the exhibit. Using VLSM, what is the largest and smallest subnet mask required on this network in order to minimize address waste?

255.255.254.0 and 255.255.255.252 The largest subnet requires 500 hosts addresses, so the most efficient subnet would be a /23 with the mask 255.255.254.0. The smallest subnet, the links between the routers, requires two addresses each, so a /30 subnet with the mask 255.255.255.252 is required.

A network administrator has been issued a network address of 192.31.7.64/26. How many subnets of equal size could be created from the assigned /26 network by using a /28 prefix?

4 A /26 prefix requires the first 2 bits of the last octet for the network portion. The last octet of the assigned network address (64) is 0100 0000 with the first 2 bits reserved for the network portion. Our beginning values go from 192.31.7.64 through to 192.31.7.127. If we now further subdivide that range using a /28 prefix, we need to borrow 2 more bits. Remember that to remain within the .64 to .127 range, the first two bits MUST remain as 01. Because we have only 2 more bits to work with, there are only 4 different combinations. 192.31.7.64 - 0100 0000 192.31.7.80 - 0101 0000 192.31.7.96 - 0110 00000 192.31.7.112 - 0111 00000 Notice that the subnets increment by 16.

The administrator of a branch office receives an IPv6 prefix of 2001:db8:3000::/52 from the corporate network manager. How many subnets can the administrator create?

4096 9.3.1 Subnetting an IPv6 Network

A PC that is communicating with a web server is utilizing a window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. What byte of information will the web server acknowledge after it has received four packets of data from the PC?

6,001 7.2.2 Reliability and Flow Control

Refer to the exhibit. HostA is attempting to contact ServerB. Which two statements correctly describe the addressing that HostA will generate in the process?

A frame with the destination MAC address of RouterA. A packet with the destination IP address of ServerB.

A nibble consists of?

A nibble is half of a byte or 4 bits. This is significant because subnetting in IPv6 is usually done on a nibble boundary.

A user is attempting to do an http://www.cisco.com/ without success. Which two configuration values must be set on the host to allow this access?

DNS server Default gateway

The minimum Ethernet frame size is............ bytes. Anything smaller than that should be considered a "runt frame."

Ethernet II and IEEE 802.3 standards define the minimum frame as 64 bytes and the maximum as 1518 bytes.

For which three reasons was a packet-switched connectionless data communications technology used when developing the Internet?

It can rapidly adapt to the loss of data transmission facilities. It efficiently utilizes the network infrastructure to transfer data. Data packets can travel multiple paths through the network simultaneously.

What is the effect of setting the security mode to WEP on the Linksys integrated router?

It encrypts data between the wireless client and the access point.

What is the function of CSMA/CA in a WLAN?

It provides the mechanism for media access.

Which devices should be secured to mitigate against MAC address spoofing attacks?

Layer 2 attacks such as MAC address spoofing can be mitigated by securing Layer 2 devices.

Using default settings, what is the next step in the router boot sequence after the IOS loads from flash?

Locate and load the startup-config file from NVRAM.

Refer to the exhibit. A network engineer is attempting to connect to a new router to perform the initial configuration. The engineer connects a rollover cable from the serial port of a PC to the Aux port on the router, then configures HyperTerminal as shown. The engineer cannot get a login prompt in HyperTerminal. What would fix the problem?

Move the cable to the router console port.

A network team is comparing physical WAN topologies for connecting remote sites to a headquarters building. Which topology provides high availability and connects some, but not all, remote sites?

Partial mesh topologies provide high availability by interconnecting multiple remote sites, but do not require a connection between all remote sites. A mesh topology requires point-to-point links with every system being connected to every other system. A point-to-point topology is where each device is connected to one other device. A hub and spoke uses a central device in a star topology that connects to other point-to-point devices.

Which two types of applications rely on their traffic having priority over other traffic types through the network?

Real-time applications, such as voice and video, rely on optimized treatment compared to other traffic on the network in order to provide reliable service.

Which two statements are correct in a comparison of IPv4 and IPv6 packet headers?

The Source Address field name from IPv4 is kept in IPv6. The Time-to-Live field from IPv4 has been replaced by the Hop Limit field in IPv6. The IPv6 packet header fields are as follows: Version, Traffic Class, Flow Label, Payload Length, Next Header, Hop Limit, Source Address, and Destination Address. The IPv4 packet header fields include the following: Version, Differentiated Services, Time-to-Live, Protocol, Source IP Address, and Destination IP Address. Both versions have a 4-bit Version field. Both versions have a Source (IP) Address field. IPv4 addresses are 32 bits; IPv6 addresses are 128 bits. The Time-to-Live or TTL field in IPv4 is now called Hop Limit in IPv6, but this field serves the same purpose in both versions. The value in this 8-bit field decrements each time a packet passes through any router. When this value is 0, the packet is discarded and is not forwarded to any other router.

Refer to the exhibit. What will be the result of entering this configuration the next time a network administrator connects a console cable to the router and no additional commands have been entered?

The administrator will be presented with the R1> prompt. 6.4.1 Configure Initial Settings

A router boots and enters setup mode. What is the reason for this?

The configuration file is missing from NVRAM.

To revert to a previous configuration, an administrator issues the command copy tftp startup-config on a router and enters the host address and file name when prompted. After the command is completed, why does the current configuration remain unchanged?

The configuration should have been copied to the running configuration instead.

Refer to the exhibit. Which layer of the OSI model would format data in this way?

The data link layer PDU is referred to as a frame, which can also be seen in both the header and trailer in the exhibit. Ethernet adds both a header and a trailer to the data as it is passed down from Layer 3.

Which interface configuration mode command puts a Layer 3 switch interface into Layer 3 mode?

The no switchport command applied at the interface configuration mode puts a Layer 3 switch interface in the Layer 3 mode.

Open the PT activity. Perform the tasks in the activity instructions and then answer the question. Which information is obtained from this command output?

The nslookup command has to be used to obtain information about the FTP site. After issuing this command on the PC1 command prompt, a prompt ">" will be displayed. Then the user enters the name of the site to obtain its information which includes the address of the site (10.20.20.3) and the type of answer given by the DNS server. In this case, it was a non-authoritative answer.

A user calls the help desk to report that a Windows XP workstation is unable to connect to the network after startup and that a popup window says "This connection has limited or no connectivity." The technician asks the user to issue the ipconfig /all command. The user reports the IP address is 169.254.69.196 with subnet mask of 255.255.0.0 and nothing is displayed for the DNS server IP address. What is the cause of the problem?

The workstation is unable to obtain an IP address from a DHCP server.

A network administrator enters the service password-encryption command into the configuration mode of a router. What does this command accomplish?

This command prevents someone from viewing the running configuration passwords.

Which statement describes a characteristic of the traceroute utility?

Traceroute is a utility that generates a list of hops (or routers) along the path from a source host to the destination host.

What three primary functions does data link layer encapsulation provide?

addressing error detection frame delimiting

What makes fiber preferable to copper cabling for interconnecting buildings?

greater distances per cable run durable connections greater bandwidth potential

A medium-sized business is researching available options for connecting to the Internet. The company is looking for a high speed option with dedicated, symmetric access. Which connection type should the company choose?

leased line.

Which two functions are primary functions of a router?

packet switching path selection

Which is a function of the show ip route command when used as a tool for troubleshooting network connectivity?

shows the IP address of the next hop router for each route

What is one purpose of the TCP three-way handshake?

synchronizing sequence numbers between source and destination in preparation for data transfer. 7.2.1 TCP Communication

Why are port numbers included in the TCP header of a segment?

to enable a receiving host to forward the data to the appropriate application. 7.1.2 Introducing TCP and UDP

What are two ways that TCP uses the sequence numbers in a segment?

to identify missing segments at the destination to reassemble the segments at the remote location

Why are the paired wires twisted in a CAT5 cable?

to provide eletromagnetic noise cancellation Twisted pair provides noise cancelation because each pair represents a differential signal. The electromagnetic field generated by one wire has the same power but opposite sign than the field generated by the other wire, thereby resulting in no electromagnetic field.