Networking
The application layer in the TCP/IP protocol suite is usually considered to be the combination of ________layers in the OSI model.
"application, presentation, and session"
Which is an example of a top-level domain? .com total.com support.total.com dallas.support.total.com
.com
What is the result of ANDing binary number 1111 1111 and 0000 1111
0000 1111
What is the result of ANDing binary number 1111 1110 and 0100 0001
0100 0000
In this course, the metric units are used instead of traditional English units. 1kbps is:
1,000 bits/s
Route summarization, also called route aggregation, is a method of minimizing the number of routing tables in an IP (Internet Protocol) network. It works by consolidating selected multiple routes into a single route. We will work out a route summarization for 172.22.1.128/27 and 172.22.1.160/27 here. List 172.22.1.128 in binary format, separating octet with a dot [1] List 172.22.1.160 in binary format [2] Count the left-most matching bits to determine the mask for the summary route. They have how many [3] left-most bits in common. Copy the matching bits and fill in the remaining bits with zero, the result in binary format is [4]. The summarized network address in dotted decimal notation is[5], and the subnet mask in dotted decimal notation is [6].
10101100.00010110.00000001.10000000 10101100.00010110.00000001.10100000 26 10101100.00010110.00000001.10000000 172.22.1.128 255.255.255.192
c. If the second segment arrives before the first segment, in the acknowledgment of the first arriving segment, what is the acknowledgment number[1]?
127
What is the result of ANDing 255 and 15?
15
In a fully connected mesh topology with six end systems, _____ links are needed.
15 n(n-1)/2
A port address in UDP is _______bits long.
16
A network address of 192.168.6.0 and a subnet mask of 255.255.254.0 can be written in CIDR as?
192.168.6.0/23
Given IP address 192.168.68.210, subnet mask 255.255.255.128, the network address is:
192.168.68.128
In TCP, if the ACK value is 200, then byte _______ has been received successfully.
199
Host A and B are communicating over a TCP connection, and Host B has already received from A all bytes up through byte 126. Suppose Host A then sends two segments to Host B back-to-back. The first and second segments contain 80 and 40 bytes of data, respectively. In the first segment, the sequence number is 127, the source port number is 302, and the destination port number is 80. Host B sends an acknowledgment whenever it receives a segment from Host A. a. In the second segment sent from Host A to B, what are the sequence number[1], source port number[2], and destination port number[3]?
207 302 80
b. If the first segment arrives before the second segment, in the acknowledgment of the first arriving segment, what is the acknowledgment number[1], the source port number[2], and the destination port number[3]?
207 80 302
Which of the following is the Incorrect IP address? 213.231.56.4 253.251.256.0 176.9.59.4 188.40.139.40
253.251.256.0
Which of the following is the correct subnet mask? 0.255.255.255 255.255.241.0 255.255.1.0 255.224.0.0
255.224.0.0
We are sending a 30 Mbit file from source host A to destination host B. All links in the path between source and destination have a transmission rate of 10 Mbps. Assume that the propagation speed is 2 * 108 meters/sec, and the distance between source and destination is 10,000 km. The end-to-end delay (transmission delay plus propagation delay) is:
3.05sec
An IPv4 address consists of _______ bits.
32
In a star topology with six computers, _____ links are needed
6
What is the result of ANDing 192 and 65?
64
The IP address 192.168.20.5 is an example of what?
A private IP address
Which of the following sequence of packets best describes the first set of messages used in a TCP connection when host A wants to establish a TCP connection with host B?
A sends to B a SYN packet, (2) B sends to A a SYN packet with an ACK, (3) A sends to B a normal packet (i.e., no SYN flag set) with an ACK
Which of the following are valid DNS record entry types? A M NS SOA
Answers A, C, D
Which of the following is not a function of the network layer?
Application data analysis
_________ can impair a signal.
Attenuation Distortion Noise
Most networks can run at speeds of up to 1000 Mbps, most new cabling installations use ___________cabling.
Category 5e
_______ data have discrete states and take discrete values.
Digital
A message M is encapsulated by the TCP, IP and Ethernet protocols in that order as it travels down a protocol stack. What does the frame look like when observed on the Ethernet link? T for TCP header, similarly for I and E, and M for the message.
EITM
In TCP/IP model, a packet at the third layer carries data belonging to the ________ layer and the header belonging to the _________ layer.
Fourth; third
IP: 135.46.57.14
Interface 0
A router has the following (CIDR) entries in its routing table: Address/mask Next hop 135.46.56.0/22 Interface 0 135.46.60.0/22 Interface 1 192.53.40.0/23 Router 1 0.0.0.0/0 Router 2 For each of the following IP addresses in question 1-5, where does the router forward it if a packet with that address as destination IP address arrives? IP: 135.46.63.10
Interface 1
What is an advantage that UDP has over TCP?
Low overhead
When a datagram is encapsulated in a frame, the total size of the datagram must be less than the _______.
MTU
______________ means accepting items from more than one source. ______________ means delivering items to more than one source.
Multiplexing_ Demultiplexing
You just turned on a four port Ethernet switch (it hasn t learned any addresses yet), and connected a host to each port. You send packet #1 from 00:11:22:33:44:55 to 66:77:88:99:00:11 which arrives at port 1 of your switch. Next, packet #2 is sent from 22:33:44:55:66 to 00:11:22:33:44:55 which arrives at port 3 of your switch. Which of the following are true?
Packet #2 is only sent out on port 1
What does the transport layer use to track application conversations?
Port numbers
One of the responsibilities of the transport layer protocol is to create a ______ communication.
Process to process
When a message fails to deliver the first time, how will TCP respond?
Resend the unacknowledged segments
IP: 192.53.40.7
Router 1
IP: 135.46.52.2
Router 2
IP: 192.53.56.7
Router 2
Which three layers of the OSI model make up the application layer in the TCP/IP model?
Session, presentation, and application
Which piece of information about a route that a routing table doesn t contain
Source address
"In the TCP/IP protocol suite, which of the following is an application layer protocol?" The User Datagram Protocol (UDP) The Internet Protocol (IP) The File Transfer Protocol (FTP) The Transmission Control Protocol (TCP)
The File Transfer Protocol (FTP)
"In the TCP/IP protocol suite, which of the following is a transport-layer protocol?" The Internet Control Message Protocol (ICMP) The Internet Protocol (IP) The Address Resolution Protocol (ARP) The Transmission Control Protocol (TCP)
The Transmission Control Protocol (TCP)
Which of the following is a function of the iterative query type?
The client queries a DNS server and instructs the server that it expects the best answer the server can provide without seeking help from other DNS servers.
Entering nslookup at the command prompt will provide which of the following?
The default name server for your host
In which scenario will the transport layer at the destination use HTTP to retrieve a web page from a web server? The header contains the HTTP port of 110. Port 21 is listed as the source port in the header The source port in the header is 23. The destination port in the header is 80.
The destination port in the header is 80.
Assume transmission rate of the link from host A to host B has been upgraded from 10 Mbps to 100 Mbps. Which of the following is true? The total delay decreases 10 times The transmission delay increases 10 times The propagation delay increases 10 times
The transmission delay decrease 10 times
What happens if a UDP message is lost due to network error on the way from client host to server host?
UDP client does not do anything
In IPv4, class _______ has the greatest number of addresses in each block.
a
An HTTP request message always contains _______.
a request line and a header
A response message always contains _______.
a status line and a header
TCP uses _________________ to check the safe and sound arrival of data.
an acknowledgment mechanism
A client program normally uses ____________ port number. A server program normally uses __________ port number.
an ephemeral_ a wellknown
An ARP request is normally _______.
broadcast
In a _____________ communication, the media needs to be shared between devices.
bus
Routers in the path are not allowed to ___________________________.
change source or destination address
UDP is called a ________________transport protocol.
connectionless, unreliable
The TCP acknowledgment number is ________.
cumulative
When a student enters a Wi-Fi hotspot on campus, she can log on to the Internet. Which protocol contributes to making this possible by assigning her device an IP address?
dhcp
Which is not a component of the web address http://news.com/index.htm ?
dns
Which protocol is responsible for converting text Internet addresses (for example , www.google.com ) into numeric Internet addresses?
dns
DNS can use the services of ________.
either UDP or TC
Which application would be better suited to TCP?
Address Resolution Protocol (ARP) assigns a unique MAC address to each
false
Address Resolution Protocol (ARP) assigns a unique MAC address to each node
false
In TCP, the sequence number for each segment is the number of the _______ byte (virtual byte) carried in that segment.
first
_____________ is a language for creating Web pages.
html
Which of the following commands clears the local cache of DNS entries?
ipconfig /flushdns
The network layer in the Internet provides _________________.
limited error control, but no flow control
A host computer is assigned the IP address 192.168.12.8 and a subnet mask of 255.255.255.192. The host sends a packet to another host with an IP address of 192.168.12.65. Is the destination IP address in the same subnet as 192.168.12.8?
no
In TCP, an ACK segments that carry no data consumes _______ sequence number(s).
no
In a ___________ connection, one TCP connection is made for each request/response.
nonpersistent
In a URL, the _______ is the full name of the file where the information is located.
path
HTTP version 1.1 specifies a _________connection by default.
persistent
In a URL, the _______ is the client-server program used to retrieve the document.
protocol
In HTTP, a _______ server is a computer that keeps copies of responses to recent requests."
proxy
the bytes of data being transferred in each connection are numbered by TCP. The numbering starts with a __________________.
randomly generated number
In __________ resolution, the resolver expects the server to supply the final answer.
recursive
Which servers are at the top of the DNS hierarchy?
root servers
What device would permit hosts on different subnets to be able to communicate?
router
A cookie is made by the _______.
server
Which topology requires a central controller or hub?
star
HTTP uses the services of _________ on well-known port 80.
tcp
If the fragment offset has a value of 100, it means that _______
the first byte of the datagram is byte 800
In TCP/IP, a message at the application layer is encapsulated in a packet at the ________ layer.
transport
UDP and TCP are two protocols at the ___________ layer.
transport
IP header checksum is designed to detect errors only within the IP header
true
If one fragment of an IP datagram is lost, the other fragments are discarded by the destination host.
true
In UTP, each colored pair is twisted a different number of times. In another word, the twisted rate is different from pair to pair.
true
Transport and Application layer of the Internet protocol stack are implemented in the end systems but not in the routers in the network core.
true
Use of DHCP guarantees that all hosts on a given network can always obtain a unique IP address.
true
