Describe the Operation of data networks Flashcards
1
Q
What is the primary difference between routing and bridging.
A
Bridging takes place at OSI Layer2, and routing takes place at OSI Layer 3.
2
Q
What is the cause of Jitters in the IP network?
A
network congestion
3
Q
What UDP port is used by the ICMP Echo feature to communicate network connectivity status messages for a target host.
A
UDP Port 7
4
Q
What TCP port does File Transfer Protocol (FTP) use to communicate with other hosts?
A
TCP port 21
5
Q
What is the term used for the Transmission Control Protocol (TCP) error recovery and windowing process?
A
Positive Achnowledgement and Retransmission (PAR)
6
Q
What TCP packet header field specifies the maximum number of unacknowledged bytes allowed at any given point of time?
A
the Window field
7
Q
What Layer 2 network devices forward frames based on a MAC address table which is dynamically populated as the device learns new MAC addresses?
A
Switches
8
Q
What feature of ICMP protocol is used by the ping command to verify network connectivity to the target host?
A
ICMP Echo
9
Q
Routing metrics are characteristics of which type of protocols?
A
routing protocols
10
Q
Which UDP port does Trivial File Transfer Protocol (TFTP) use to communicate with other hosts?
A
UDP port 69
11
Q
Which TCP mechanism limits the amount of data transfer between hosts to an acceptable speed?
A
flow control
12
Q
Which protocol requires the receiving station to acknowledge the receipt of packets; TCP or UDP?
A
TCP
13
Q
What routing metric enables a router to decide the best path through the network based on the maximum attainable throughput on a link?
A
bandwidth
14
Q
What would be the destination MAC address for a host sending a packet to another host across a router?
A
The MAC address of the router
15
Q
Which Layer 2 devices provide hardware-based switching of LAN traffic?
A
LAN switches
16
Q
Which technology defines a way to carry voice calls over an IP network by digitizing and packetizing the analogue voice signals?
A
Voice over IP or (VoIP)
17
Q
What is the term used for the router which receives clock synchronization from another router in a Point-to-Point WAN link?
A
Data Terminal Equipment (DTE)
18
Q
How many fields are in a TCP packt header?
A
12
19
Q
What routing metric enables a router to make a routing decision based on the extent to which a link is busy?
A
load
20
Q
Which protocol enables hosts on a LAN segment to determine the MAC address of hosts with known IP addresses?
A
Address Resolution Protocol (ARP)
21
Q
Which network device enables two hosts on dissimilar networks to communicate with each other?
A
a router
22
Q
Which TCP port does HTTP use to communicate with other hosts?
A
TCP port 80
23
Q
Which network devices operate at OSI Layer 1 and provide multiple ports to connect many hosts on the network?
A
Hubs
24
Q
The network device that only provides the conversion from copper based media transmission technology to optical fiber based media transmission technology operates at which OSI Layer?
A
OSI Layer 1
25
Which ICMP message will be generated if the TYPE field of the ICMP packet header has a value of 11?
Time Exceeded
26
Which TCP port does telnet use to communicate with other hosts?
TCP port 23
27
Which Cisco IOS command is used to enable the CDP on a Cisco device?
the
**cdp run**
global configuration command
28
What type of networking device is required to host a T1 Connection?
Router
29
Which device connects a router to a T1 WAN connection that converts WAN signals into signals that the LAN can understand, and also monitors and controls the WAN Link?
Channel service Unit / Data Service Unit
(CSU/DSU)
30
What is the maximum acceptable delay allowable between two voice packets?
150 ms
31
What is another term for TCP Windowing?
flow control
32
What is the default TCP segment payload (in bytes)?
536 bytes
33
What Layer 2 devices provide wireless access to Wi-Fi enabled hosts on the Network?
Access Points
34
What is the default CDP hold time?
180 Seconds
35
What TCP port does the World Wide Web (WWW) use to communicate with other hosts?
TCP port 80
36
What ICMP message will be generated if the TYPE field of the ICMP packet header has a value of 3?
Destination Unreachable
37
At which OSI Layer should you begin troubleshooting if the router interface reports that the protocol and the interface are down?
OSI Layer 1
38
From the telephone company's standpoint, what is the term used for the point that defines the boundary between the responsibilities of the customer and the service provider?
Demarcation Point (demarc)
39
What is the term used for the WAN device that are installed at the customer site by the telecommunications company?
Customer Premises Equipments (CPE)
40
Which device provides the clock rate to routers?
CSU/DSU
41
What TCP port does the Simple Mail Transfer Protocol (SMTP) use to communicate with other hosts?
TCP port 25
42
Which multicast destination MAC address is used by CDP to make announcements?
01-00-0c-cc-cc-cc
43
Which TCP port does Post Office Protocol -Version POP3 use to communicate with other hosts?
TCP port 110
44
Which Cisco IOS feature causes network devices to give preference to voice traffic to ensure the smooth transmission of voice traffic?
Quality of Service (QoS)
45
At what router prompt is the router **ip address** command excuted?
**router(config-if)#**
46
What is the size of the Source field or Destination field in a TCP packet header?
16 bits
47
What routing metric is used by RIPv2 tp determine the best route to a destination?
hop count
48
What is the term used for the device which provides clock synchronization to a router in a Point-to-Point WAN link?
Data Communication Equipment (DCE)
49
Which Cisco OCI command is used to reset CDP traffic counter to Zero?
the
**clear cdp counter**
privileged EXEC command
50
What is the term used for the parameters by which a router determines the best path to the destination host?
router metrics
51
What must be the value of the two most significant bits in a Class B IP address?
10
52
Which port is used by Simple Network Management Protocol (SNMP) to communicate with other hosts?
UDP port 161
53
Which OSI Layer 2 devices provide software-based switching of LAN traffic?
LAN bridges
54
What is the size of the Control field in a TCP packet header?
6 bits
55
Which Cisco IOS command would display information collected by CDP about traffic details between devices?
the
**show cdp traffic**
privileged EXEC mode command.
56
What is the term used for a type of delay variation that is characteristic of voice traffic?
jitters
57
Which Layer 2 devices implement the Spanning Tree Protocol (STP) feature?
switches
58
Which Cisco IOS CDP **show** command displays the interface on which CDP is enabled?
the
**show cdp interface**
privileged EXEC mode command
59
At which OSI layer does the Internet Protocol (IP) operate?
Network Layer
Layer 3
60
Which TCP packet header field specifies the number assigned to the first byte in the message sent?
Sequence Number
61
Which device connects the 4-wire cable of the ISP WAN and the router?
CSU/DSU
62
Which TCP packet header field tells the sender how much data can be transmitted before the sender should stop and wait for acknowledgement?
The Window field.
63
Which Cisco OSI layer does the Cisco Discovery Protocol (CDP) operate?
Layer 2
64
Which device will provide network connectivity to 200 hosts on the LAN and allocate dedicated bandwidth to each of the hosts?
a Switch
65
Which protocol is used by the ping utility command to test the networking connectivity of the destination host?
Internet Control Message Protocol
(ICMP)
66
At which OSI layer do the wireless access points operate?
OSI Layer 2
67
What is the size of the Windows field in a TCP packet header?
16 Bits
68
Which routing metric is defined as the time that the Internet Protocol (IP) packet takes to travel from source to destination?
delay
69
What is the size of the Acknowledgement Number field in a TCP packet header?
32 Bits
70
Which ICMP message will be generated if the TYPE field of the ICMP packet header has a value of 0?
Echo Reply
71
Which type of ICMP message is generated when a router faces congestion at any of its interfaces?
ICMP Source Quench message
72
Which dedicated software or hardware device is used to permit, deny or filter data packets based on different trust levels?
a firewall
73
Which type of traffic includes core business applications that are considered critical to the enterprise operations?
mission-critical traffic
74
Which protocol is connectionless: Simple Mail Transfer Protocol (SMTP) or User Datagram Protocol (UDP)?
UDP
75
What type(s) of cabling is required for a 250-meter cable run?
Fiber or ThickNet coaxial
76
Which ICMP message is sent by the router to the source host to use more efficient routing?
ICMP Redirect message
77
Which UDP port does the Domain Name Server (DNS) protocol use to communicate with other hosts?
UDP port 53
78
Which Cisco IOS command is used to enable the Cisco Discovery Protocol Version 2 (CDPv2) advertising feature on a Cisco device?
the
**cdp advertise-v2**
global configuration command
79
What is the unit of data at the OSI data link layer?
Frames
80
Which OSI layer uses IP addressess to communicate with hosts?
Network Layer
Layer 3
81
Where does the router store the paths to different networks?
The routing table
82
Which Cisco IOS CDP **show** command can be used to verify whether CDP is enabled on a particular device?
the
**show cdp neighbors**
command
83
At which OSI layer shoud you start troubleshooting if the router interface reports that the protocol is down but the interface is up?
OSI Layer 2
84
Which TCP port does Post Office Protocol - Version 2 (POP2) use to communicate with other hosts?
TCP port 109
85
What is the name given to the realtime management of the number of packets handled by TCP that can be received without an acknowledgement?
windowing
86
Which network device provides a common connection point for network hosts and operates at OSI Layer 1?
a hub
87
What are the three approaches for troubleshooting network problems using the OSI layered model?
Bottom Up
Top Down
Divide and Conquer
88
Which device converts telephonic signals to digital signals and vice versa to enable a computer to connect to the Internet?
a modem
89
Which TCP packet header field contains the control information used for connection establishment?
The Flags field
90
What is the name given to the protocol data unit (PDU) at the transport layer?
Segment
91
How many fields are in a User Datagram Protocol (UCP) packet header?
4
92
What is the name given to the protocol data unit (PDU) at the data link layer ?
Which layer is the Data Link layer?
frame
Layer 2
93
What are the two types of delays that are also characteristic of real-time traffic?
fixed delay and variable delay
94
Which Cisco proprietary protocol operates at OSI Layer 2 but is capable of obtaining OSI Layer 3 IP address information for directly connected neighboring devices?
Cisco Discover Protocol (CDP)
95
Which TCP port is used by ICMP Echo feature to communicate network connectivity status messages for a target host?
TCP port 7
96
Which protocol is connection-oriented: TCP or UDP
TCP
97
What is the default interval used by CDP to send updates?
60 seconds
98
Which Cisco IOS Discovery Protocol (CDP) **show** command will display the IP address of the connected device?
the
**show cdp neighbors detail**
privileged EXEC mode command
99
Which OSI Transport Layer protocol is used by Simple Network Management Protocol (SNMP)?
UDP
100
Which Cisco IOS Command is used to clear the table that contains the CDP information about neighboring devices?
the
**clear cdp table**
privileged EXEC command
101
Which Layer 3 devices are used to segregate a network into separate broadcast domains?
routers
102
Which netowrk device would you use to connect two networks on different IP subnets?
Router
103
What is the term used for the variation in the delay between two voice packets?
jitters
104
Which ICMP message will be generated if the TYPE field of the ICMP packet header has a value of 8?
Echo Request
105
Which TCP packet header field contains the sequence number of the next byte of data that will be sent to the sender of the packet?
the Acknowledgement Number field.
106
Which uses less packet overhead Voice traffic or Data traffic?
data traffic
107
At which OSI Layer should you start troubleshooting network communication problems if there are data errors due to kinks in the LAN cables?
OSI Layer 1
108
What is the size of the Sequence Number field in a TCP packet header?
32 bits
109
What is the name of one data unit at the OSI Network Layer?
a packet
Layer 3
110
Which OSI Layer 2 software feature allows the creation of broadcast domains on the switch?
Virtual Lan (VlLAN)
111
What are three issues inherent to a converged network that can adversely affect voice and video traffic?
bandwidth
packet loss
and delays
112
What command is used to enable an interface?
**no shutdown**
113
Which CDP feature allows CDP to include routing information in its periodic update messages to neghboring devices?
On-Demand Routing (ODR)
114
At which OSI Layer does the User Datagram Protocol (UDP) operate?
transport layer
Layer 4
115
Which OSI transport Layer protocol is used by Domain Name Seystem (DNS) and Trivial File Transfer Protocol (TFTP)?
UDP
116
What is the term used for process in which the acknowledgement field in TCP packet communicates information to the receiving host about the next byte to be received?
forward acknowledgement
117
At what router prompt is the **configure terminal** command executed?
**router#**
118
At which layer of the OSI model does the windowing process occur to control the flow of data between sender and receiver?
transport layer
Layer 4
119
How many octets of an IP address represent the network portion in a Class C address?
the first three octets
120
What is the name of the data unit at the OSI transport layer (Layer 4)?
a segment
121
From an Internet Service Provider (ISP) standpoint, what is the term used for the edge communication equipment at the customer's location that connects the customer to the ISP network?
Customer Premises Equipment (CPE)
122
Which network device provides filtering for packets based on the transport layer protocol specification?
routers, via the use of extended access control lists
123
How many times does the source and destination MAC address of a packet change when a host sends a message to another host across a router?
Once; when the packet is routed from the source LAN segment to the other segment.
124
What is the default status of CDP version 2 advertisements on a Cisco device?
CDP Version 2 advertisements are enabled by default.
125
Which protocol has less packet overhead; TCP or UDP?
UDP
126
Which ICMP message will be generated if the TYPE field of the ICMP packet header has a value of 4?
Source Quench
127
Which TCP packet header field indicates whether the header was damaged in transit?
the Checksum field
128
What is the term used for IP packets that carry voice signals between two IP phones?
Voce over IP (VoIP)
129
Which OSI Layer 2 hardware device is used to create separate collision domains?
Switches
130
What is the term used for the number of devices through which a packet passes when traveling from a source to a destination?
hop count
131
What is the default status of CDP on a Cisco device interface?
CDP is enabled by default
132
Which OSI layered troublshooting model suggests that you should begin troubleshooting from the top-most OSI application layer?
Top Down
