This quiz is a revised and updated (by Dr. Debby Koren) version of a quiz that was written by students at Tel Aviv University
Choose the correct statement about Ethernet
The maximum frame size is less than 1500 bytes
The minimum frame length is less than 500 bytes
Answer A and B are correct
The maximum frame size is 1518 bytes and the minimum frame length is 512 bytes, including the header
Choose the correct statement about the Ethernet access mechanism
If a collision is detected, transmission is aborted and retransmission occurs after a constant period of time
If the device does not receive an acknowledgment on a transmission, it retransmits
All devices have equal access rights
A device wishing to transmit does not have to check if the channel is clear
Which statement is true about Ethernet and 802.3?
They are two protocols that differ on the Physical Control Layer
They are two protocols that differ on Data Link Layer
802.3 can work with an acknowledgment mechanism but Ethernet can not
Answers B and C are right
Choose the correct description of Ethernet
Reliable protocol that works on a broadcast medium
Half duplex protocol that has an acknowledgment mechanism
Connection oriented protocol and half duplex
Protocol that based on a datagram delivery and a broadcast medium
Choose the correct statement about Local and Wide Area Networks (LAN/WAN)
A LAN is limited in geographical scope and has relatively high error rates
A WAN has higher delays and higher costs than LAN
WAN can connect only routers
LAN has relatively low data and error rates
Which of the following protocols is different?
FDDI
Frame Relay
Ethernet
Token Ring
Which of the following devices is different?
bridge
repeater
router
hub
Which is an incorrect statement about the infrastructure layer (physical and data link layer) devices?
Bridges connect Local and Wide area networks
Repeaters allow multiple collision domains
There is a limit on number of repeaters in LAN
There is no limit on number of bridges
Choose the correct statement about infrastructure (physical and data link) layer devices
Bridges store and forward complete packets while repeaters forward all electrical signals
Bridges use physical addresses while L2 switches use IP addresses
Switches work more slowly than bridges
Hubs are like multi-port bridges
Choose the incorrect statement about the bridges
A bridge is a MAC layer store and forward device
A bridge learns the MAC address for each station transmitting on each connected network
A bridge floods frames destined for stations not yet learned by transmitting on all interfaces
All of the above
Which protocol is different?
T1
E3
IEEE 802.3
X.25
Choose the incorrect statement about virtual circuit packet switching
Each packet may pass via a different route
X.25, Frame Relay, and ATM are all virtual circuit packet switching protocols
Virtual circuit packet switching is connection oriented
If one link in the path fails, the connection must be reestablished
Voice traffic is not characterized by
Uniform delay
Traditionally based on circuit switching protocols
Tolerates high error rates
Traffic is bursty
Choose the incorrect statement about ISDN
ISDN is a public network that provides end to end digital transmission
It supports voice and non-voice services
It provides variable bandwidth for each channel according to the demands of the user
All of the above
Choose the correct statement about the X.25 protocol
X.25 is a circuit switching protocol based on physical links
It is a simple protocol in which there is no a retransmission mechanism
It is a simple protocol in which there is no an acknowledgement mechanism for transmission
None of the above
Choose the incorrect statement about the Frame Relay protocol
Frame Relay has physical and frame layers
It relies on procedures in higher protocol layers
It is used over analog noisy circuits
All of the above
Choose the correct statement about ATM protocol
ATM is an implementation of the Cell Relay technology
It is a fast packet switching implementation
It is a datagram delivery implementation
Answers A and B are correct
Choose the incorrect statement about the ATM protocol
ATM has an error correction mechanism
ATM has an error detection mechanism
ATM uses small cells
Cells are assigned asynchronously to the services
Choose the correct statement about features of wide area technologies
Circuit switching supports high speed data and sharing of the same channel to carry voice, data, and video
X.25 handles voice traffic
With a leased line (point to point link) bandwidth is used even when there is nothing to transmit
Cell Relay can handle voice traffic but not a shared channel for voice, data and video
Choose the correct statement about features of different protocol
X.25 can be used for LANs as well as for a WAN
ATM can be used for LANs as well as for a WAN
E1/T1 can be used for LANs as well as for a WAN
None of the above
You want to guarantee the transmission of data for long distances with minimum payment. Which technology will you choose?
Ethernet
Frame Relay CIR-0
Frame Relay CIR-128
Dedicated point-to-point link
On a given router, which of the following situations is impossible?
Two IP addresses on the same interface
The same IP address on two different active interfaces
Two different IP addresses but one physical address
None of the above
In the IP header, which protocol can not appear in the protocol field?
ICMP
ARP
UDP
None of the above
Which of the following messages is not an ICMP message?
Ping request
Redirect
Time exceeded
None of the above
Which protocol is different?
RIP
DHCP
OSPF
BGP
Classical IP and ARP over ATM is a protocol at the
Physical Layer
Data Link Layer
Network (IP) Layer
Network Interface Layer
If a router with IP addresses 203.168.27.14 and 198.20.30.15 (and default masks) and physical addresses xxxxx and yyyyy receives the message with IP destination address 128.20.30.15 and physical address xxxxx, what should the router do?
Discard the message
Pass the message to its next higher layer
Pass the message to another router
Pass the message to the ultimate destination
If a router with IP addresses 203.168.27.14 and 198.168.27.15 (and default masks) and physical addresses xxxxx and yyyyy receives a message with IP destination address 203.168.27.15 and physical address xxxxx, what should the router do?
Discard the message
Pass the message to its next higher layer
Pass the message to another router
Pass the message to the ultimate destination
If a router with IP addresses 203.168.27.14 and 198.20.30.15 (and default masks) and physical addresses xxxxx and yyyyy receives a message with IP destination address 198.20.30.15 and physical address zzzzz, what should the router do?
Discard the message
Pass the message to its next higher layer
Pass the message to another router
Pass the message to the ultimate destination
If a host with IP address 203.168.27.14 and physical address xxxxx receives a message with IP destination address 203.168.27.15 and physical address xxxxx, what should the host do?
Discard the message
Pass the message to its next higher layer
Pass the message to its default router
Pass the message to the ultimate destination
A host with IP address 128.127.13.14 wants to send a message to a station with IP address 203.13.14.127. What should the host do?
Send the message to a default router
Send the message directly to the station
The host can send message to the station only if the station is a router
Send the message to a router according to the routing table
A router with IP addresses 203.168.27.14 and 198.20.30.15 and physical addresses xxxxx and yyyyy receives a message with IP destination address: 198.20.30.15 and physical address: yyyyy. What should the router do?
Discard the message
Pass the message to its next higher layer
Pass the message to another router
Pass the message to the ultimate destination
Which address is the loopback address?
10.0.0.0
10.0.0.1
127.0.0.0
127.0.0.1
Which address is different?
198.168.27.11
192.186.11.27
172.16.27.11
172.14.72.11
What is the default subnet mask of IP address 223.14.68.7?
255.0.0.0
255.255.0.0
255.255.255.0
It is not a legal unicast address
What is the default subnet mask of IP address 224.41.68.7
255.0.0.0
255.255.0.0
255.255.255.0
It is not a legal unicast address
Given the IP network address 112.172.13.15. Assuming the default mask, what is its network-id and host-id?
Network-id 112 and host-id 172.13.15
Network-id 112.172 and host-id 13.15
Network-id 112.172.13 and host-id 15
It is not a legal unicast address
Given a host with IP address 192.14.64.93 and the mask 255.255.255.224. To which subnet does it belong?
192.14.64.0
192.14.64.64
192.14.64.96
192.14.64.224
Given the IP network address 203.14.68.0 and the mask 255.255.255.224. Which subnet can you have with the given address and mask?
203.14.68.0
203.14.68.48
203.14.68.128
203.14.68.16
Given the IP network address 192.48.5.0/24. What CIDR prefix should you use if you want to divide it into at least 3 subnets and the maximum number of hosts per network?
/17
/26
/27
/18
You are given the IP network address 196.58.27.0/24. If you use prefix /28, how many subnets and hosts can you have?
16 subnets and 14 hosts on each subnet
14 subnets and 14 hosts on each subnet
30 subnets and 30 hosts on each subnet
16 subnets and 16 hosts on each subnet
You are given the IP network address 203.127.14.0/24. If you use the prefix /26, how much of the address space (expressed in number of hosts) is wasted due to the subnetting?
0
74
130
6
Which of the following addresses can not be that of a subnet?
204.168.13.1
204.168.13.2
204.168.13.3
All of the above
Choose the incorrect statement about the ARP protocol
It maps IP addresses to physical addresses
ARP messages are encapsulated in IP datagrams
ARP works on all broadcast media
None of the above
Choose the correct statement about ARP and routing tables
Only routers have a routing table
Only hosts have an ARP table
Hosts have an ARP table but not a routing table
Both hosts and routers have an ARP table and a routing table
Given the host with the IP address 170.213.14.1 and the default mask. Which of the following addresses can not be in its ARP table?
170.213.1.14
170.312.1.14
170.213.41.1
None of the above
Given the host with the IP address 204.127.11.53/27. Which of the following addresses can not be in its ARP table?
204.127.11.31
204.127.11.41
204.127.11.51
204.127.11.61
Given the router with addresses: 168.127.114.5/16 and 192.14.15.9/24. Which entry can not be in its routing table?
Destination: 192.14.15.192 Next Hop: 192.14.15.9 Type: direct
Destination: 192.14.14.192 Next Hop: 192.14.15.10 Type: indirect
Destination: 168.172.114.0 Next Hop: 168.127.114.5 Type: direct
Destination: 168.172.114.0 Next Hop: 168.127.114.6 Type: indirect
Given the router with addresses: 128.17.114.5/16 and 203.114.15.9/24. Which entry can not be in its routing table?
Destination: 203.114.15.0 Next Hop: 203.114.15.9 Type: direct
Destination: 128.17.114.0 Next Hop: 128.17.114.5 Type: indirect
Destination: 204.114.15.0 Next Hop: 203.114.15.33 Type: indirect
Destination: 204.114.14.0 Next Hop: 203.114.15.43 Type: indirect
Given the router with addresses: 172.14.114.5/16 and 198.114.15.9/24. Which entry can not be in its routing table?
Destination: 172.14.114.0 Next Hop: 198.114.15.9 Type: direct
Destination: 198.114.15.0 Next Hop: 198.114.15.9 Type: direct
Destination: 172.14.114.0 Next Hop: 172.14.114.5 Type: direct
Destination: 198.114.16.0 Next Hop: 198.114.15.5 Type: indirect
Choose the correct description of the TCP protocol
Reliable datagram transport protocol
Unreliable datagram transport protocol
Reliable stream transport protocol
Reliable stream network protocol
Which function does the TCP protocol NOT provide?
Virtual circuit
Connectionless service
Connection establishment and termination
Choices A and B
Which function does the TCP protocol NOT provide?
Error control
Path control (routing)
Flow control
Choices A and B
Which function does the TCP protocol NOT provide?
Addressing
Network management
Sequencing
Choices A and B
Which function does the TCP protocol NOT provide?
Multiplexing service
Full duplex connection
(Physical) Line or Connection status
Choices A and B
Choose the correct statement about TCP flow control and reliability mechanisms
Sliding window is a flow control mechanism
Retransmission is a flow control mechanism
Sliding window is a reliability mechanism
Answers A and B are correct
Choose the correct statement about the checksum mechanism
In UDP there is no checksum mechanism
In TCP the checksum is only of the header
In IP the checksum is only of the data
None of the above
Choose the incorrect statement about acknowledgement mechanisms
In UDP there is no an acknowledgement mechanism
TCP always works with an acknowledgement mechanism
In TCP there is an acknowledgement of each segment
None of the above
Choose the correct statement about the sequence and the acknowledgement numbers that appear in the SAME TCP header
Both of them refer to the stream flowing in the same direction as the segment
Both of them refer to the stream flowing in the opposite direction from the segment
The sequence number refers to the stream flowing in the same direction as the segment, while the acknowledgement number refers to the stream flowing in the opposite direction from the segment
None of the above
Choose the correct statement about the TCP acknowledgment mechanism
Lost acknowledgments force retransmissions
Lost acknowledgments do not necessarily force retransmissions
In TCP acknowledgments can not be lost
Only loss of two sequential acknowledgments or more forces retransmissions
Choose the correct characterization of the UDP protocol
Reliable stream transport protocol
User Datagram Protocol
Unreliable datagram network-layer protocol
Reliable datagram protocol
Which function does the UDP protocol NOT provide?
Checksum
Stream delivery
Connectionless service
Answers A and B are correct
UDP message can
Be lost
Be duplicated
Arrive out of sequence
All of the above
Choose the correct statement about the UDP protocol
If an application runs over the UDP protocol, acknowledgments are never sent
If an application runs over the UDP protocol, acknowledgments are never sent at the Transport level
If an application runs over the UDP protocol a socket is never opened
Answers B and C are correct
The Three-Way Handshake is
The 3-segment exchange TCP uses to establish a connection
The 3-segment exchange TCP uses to terminate a connection
Answers A and B are correct
None of the above
Choose the correct statement about port numbers
A port number is a number that distinguishes among multiple applications within a given host computer
A system administrator can specify which port number a server application will use
Some port numbers are reserved for standard services
All of the above
A well-known port is
A standardly defined port number at which a server listens
A port number on the client side that clients use to initiate connection
A port that many applications make use of
All of the above
Choose the correct statement about a port and a socket
The port number defines the application
The port and IP address (for example: (23,198.128.13.1)) define the socket
A socket pair defines a unique connection between a client and a server
All of the above
Choose the correct statement about DNS (Domain Name System)
Supports mappings between human-readable machine names and IP addresses
Supports mappings between mail destinations and IP addresses
Offers a hierarchical naming scheme
All of the above
The Computer Science Department at Tel-Aviv university chose to place the following entry in its domain name server: localhost.tau.ac.il 127.0.0.1. What will happen if a remote site tries to ping a machine with domain name localhost.tau.ac.il
Resolution of the name will be done by the local name server
Resolution of name will be done by the root name server
The ping request will not be sent
None of the above
Choose the correct statement about host names and IP addresses
Each host has a host name
Each host has a permanent IP address
The host with a host name always has a permanent IP address
None of the above
Given www.technion.ac.il. Choose the correct statement
www is a host name
"technion" is a domain
The suffix"il" is not necessary
Answers A and B are correct
Choose the correct statement about DNS
DNS requests are sent before a TCP session is opened
A host can be manually configured to know its recursive DNS server
A host can learn its recursive DNS server from DHCP
All statements are correct
Which protocol is different?
SMTP
SNMP
POP
IMAP
If I run SMTP on a station connected to an ATM network, what is my protocol stack with the TCP/IP model?
TCP/IP stack: SMTP, TCP, IP, IP over ATM; infrastructure: ATM
TCP/IP stack: SMTP, UDP, IP, IP over ATM; infrastructure: Adaptation layer, ATM, Sonet/SDH
TCP/IP stack: SMTP, TCP, IP, IP over AAL5; infrastructure: ATM Adaptation Layer 5, ATM, SDH/SONET
Answers 1 and 2 are correct
I sent an e-mail message to each of the following addresses: yyosef@eci.co.il and yosef@cei.co.il. Both of them did not reach the desired destination, the first because of an error in the name (suppose it doesn't exist) and the second because of an error in the domain (suppose it doesn't exist). Choose the correct statement.
Both of them should be returned to me
The second e-mail should be returned before the first one
The first e-mail should be returned before the second one
Answers A and B are correct
Choose the incorrect statement about SMTP (Simple Mail Transfer Protocol)
Specifies how two mail systems interact
Specifies the format of control messages two mail systems exchange to transfer mail
Highly reliable and secure protocol
None of the above
SNMP (Simple Network Management Protocol) is a protocol used to manage devices. Which devices can be managed?
Hosts
Routers
Multiplexers
All of the above
Choose the correct statement about the SNMP protocol
The NMS (Network Management System) is a server and the SNMP agent is a client
The NMS can be a client or a server.
SNMP agent can be a client or a server. This depends on an operation that is performed
Answers B and C are correct
Which of the following cannot be provided by a MIB (Management Information Base)?
TEST YOURSELF and REVIEW!