Networking Flashcards
1
Q
What are networking rules called?
A
Protocols
2
Q
What does SOHO stand for?
A
Small Office Home Network
3
Q
What is a host?
A
Any device (pc, tablet, phone, printer) connected to a network that participates in network communications
4
Q
What is throughput?
A
The amount of data sent and received over a network
5
Q
What is bandwidth?
A
The maximum capacity of the media to carry data
6
Q
Through what do mobile phones transmit voice signal?
A
Radio waves
7
Q
Why are mobile phones called cell phones?
A
Because the geographic area that a tower can provide a signal to is called a “Cell”
8
Q
What is the most common type of cellular phone network called?
A
GMS (Global System for Mobile Communications)
9
Q
What does the G stand for in 3G or 4G?
A
Generation
10
Q
What is the accuracy of a GPS?
A
10 meters
11
Q
What does NFC stand for?
A
Near Field Communication (a few centimeters)
12
Q
What is a Wi-Fi signal?
A
A radio wave
13
Q
What is the current Ethernet Standard?
A
IEEE 802.3
14
Q
What component does a device need to connect to an Ethernet LAN?
A
An Ethernet Network Interface Card (NIC)
15
Q
What are the unique addresses of devices?
A
MAC addresse
16
Q
What does MAC address stand for?
A
Media Access Control
17
Q
What is an end-user device IP address used for?
A
Identify the host on the network
18
Q
What is an end-user device subnet mask used for?
A
Identify the network on which the host is connected
19
Q
What is an end-user default gateway used for?
A
Identify the networking device that the host uses to access the Internet or another remot network
20
Q
What is a DNS server used for?
A
Translate a domain name to an IP address
21
Q
What kind of server automatically gives you an IP address?
A
A DHCP server
22
Q
Why would you want to manually configure an IP address (manual addressing)?
A
For a server, something static
23
Q
What is the most common connectivity in Ethernet networks?
A
Unshielded Twisted Pair (UTP)
24
Q
What is the most common connector on UTC cables?
A
RJ-45
25
Generally, how many copper wires are on a UTP cable?
8 wires arranged in pairs
26
What is an advantage of fiber optics
Long distance, immune to EM interference
27
What is the connector type of telephones or fax machines?
RJ-11
28
What is the advantage of a coaxial over UTP?
Better shielding
29
How many fiber optics cables is in a fiber optic circuit?
2 one to transmit, the other to receive
30
What 2 standards typically define the pinout of UTP cables?
T568A and T568B
31
What type of UTP cables do Unlike devices require?
Straight-through cables
32
What type of UTP cables do Like devices require?
Crossover cables
33
What is the name of the Traceroute utility in Windows?
tracert
34
What is each network called on a message route?
A hop
35
What are the 3 essential elements of communication?
A message source, a receiver, and a transmission medium or channel
36
What are the rules of communication called in networking?
Protocols
37
What does TCP stand for and what is it used for?
Transmission control protocol. Makes sure the message gets to its destination reliably
38
What are the 6 aspects of communication defined by protocols?
```
Timing
Message size
Encapsulation
Message format
Encoding
Message pattern
```
39
Who are the internet standards published and maintained by?
The IETF (Internet Engineering Task Force)
40
How do you call multiple protocols working together for sending a message?
A protocol stack
41
How many layers are in the standard TCP/IP model?
4
42
What are the different layers of the TCI/IP model?
Application (ex: HTTP)
Transport (ex: TCP)
Internet (ex: IP)
Network access (ex: Ethernet)
43
What is the most common reference model?
The OSI model
44
How many layers does the OSI model have?
7
45
On what OSI layers does the Ethernet protocol operate?
1 and 2
46
What type of address is used for Ethernet addressing?
MAC address
47
Who manages the Ethernet protocol?
the IEEE
48
What part of a MAC address determines the vendor?
The 3 first bytes
49
What part of the MAC address is the component's unique ID?
The 3 last bytes
50
What is the 3 first bytes of a MAC address called?
The Organizationally Unique Identifier (OUI)
51
What is encapsulation?
Like placing a letter in an envelope to add source, destination, and message
52
What is a frame?
A computer message encapsulated in a specific format
53
What is a preamble?
The first part of a frame, a 7-byte pattern of alternating 1s and 0s to synchronize timing
54
What are the 3 layers of Ethernet hierachical design?
- Access layer (connection to host on LAN)
- Distribution layer (interconnects smaller networks)
- Core layer (high-speed connection to WAN)
55
What defines the network portion of an IPv4 address from the host portion?
The subnet mask
56
What happens to the source and target MAC address of an Ethernet frame during internetwork communication?
They change
57
What is the most common Access layer device?
Switches
58
What is the most common Distribution layer device?
Routers
59
What is the most common Core layer device?
Switch route processors
60
Where do switches check to see where to send a message?
Its MAC address table
61
How do you call the temporary connection between the message source and destination that's created by a switch?
A circuit
62
What is switch flooding?
When a switch doesn't recognize a destination MAC address, it sends the message to every connected host
63
What is a broadcast?
A message sent to all hosts on a LAN
64
What is the destination MAC address of a broadcast?
FFFF.FFFF.FFFF
65
What is ARP?
Address Resolution Protocol.
| It is used to find the MAC address of a host on a LAN using its IP address
66
What are the 3 steps of the ARP process?
- Sending host broadcasts the target IPv4 address on the network
- Host with broadcasted IPv4 address replies to the broadcasting host with its MAC address
- First host stores the destination host's MAC address in an ARP table
67
Why do we divide a network? (3 reasons)
- Limit the broadcast domain
- Security reasons
- Moving things to different locations
68
How do you call devices that are beyond our local network?
Remote hosts
69
What layer does routers take their decisions on?
Layer 3, IP addresses
70
When is a router used to forward a message?
When the IP source and destination do not match
71
What does each router port connect to?
A different local network
72
How do you call the forwarding of packets towards their destination network?
Routing
73
Where do routers look to find ip addresses it knows?
In its routing table
74
What is the IPv4 address of a broadcast?
255.255.255.255
75
What does a router do if it cannot determine where to forward a message?
It drops it
76
What is the destination MAC address of a frame for a packet sent to a remote host?
The MAC address of the default gateway
77
How many bits is an IPv4 address?
32
78
What is the maximum number represented with 8 bits in binary?
255
79
What operator is used to determine network address with the subnet mask?
AND
80
How do you write the portion of a host who's subnet mask matches the first 24 bits? (192.168.3.10/255.255.255.0)
/24
81
What is the process name used by a computer to determine if an address is on its network?
Binary ANDing
82
What is a prefix length?
Shorthand of a subnet mask that says how many bits are set to 1
83
How do you calculate how many hosts can be on a network?
2^(number of host bits)-2
84
What is the name of the current addressing system?
CIDR: Classless Inter-Domain Routing
85
What is a public IPv4 address?
An address globally routed between ISP routers
86
What is a private IPv4 address?
Addresses that are not unique and that can be used in internal networks (ex: 10.0.0.0, 192.168.0.0, 172.16.0.0 etc.)
87
What translates a private IPv4 address to a public IPv4 address?
NAT, Network Address Translation
| Done by the Router connected to the IPS's network
88
Who manages and allocates the IPv4 and IPv6 addresses for the Regional Internet Registries?
The IANA (Internet Assigned Numbers Authority)
89
Who Allocates IP addresses to ISPs?
The RIR (Regional Internet Registries)
90
What is a unicast transmission?
A normal host-to-host communication, either client/server or peer-to-peer
91
What is the reserved IPv4 address range for multicasts?
224.0.0.0 to 239.255.255.255
92
What is DHCP?
Dynamic Host Configuration Protocol, used to assign an IPv4 address to a host automatically
93
Why can a router be both a DHCP client and server?
The router is a client from the ISP's DHCP server to get a public IPv4 address. The router is also a DHCP server giving a private IPv4 address to all hosts on the network
94
What is the destination IP and MAC addresses of a DHCP client's DHCP Discover broadcast?
MAC: FF-FF-FF-FF-FF-FF
IPv4: 255.255.255.255
95
What are the 4 messages exchanged between a DHCP client and server to define an IPv4 address?
DHCPDiscover (looks for DHCP server)>>
<>
<
96
What is a 169.254.x.x address and what does it mean?
It is an APIPA address (Automatic Private Internet Protocol Addressing), and it means that the DHCP server is unavailable.
97
How is the default gateway address assigned to a host?
Either manually or dynamically by DHCP
98
How long is an IPv6 address?
128 bits
99
What are 2 advantages of IPv6 addresses?
Almost infinite number of devices
| No need for NAT
100
Why use Hexadecimal?
Hex is perfect for matching 4 bits
| ex: 1 hex = 0001 bin, F hex = 1111
101
How many Hexadecimal digits is an octet?
2
102
How many hextets are in an IPv6 address?
8
103
How many bits are in a hextet?
16
104
What do subnet masks default to?
255. 255.255.0 /24
255. 255.0.0 /16
255. 0.0.0 /8
105
What do IPv6 addresses have instead of a subnet mask?
Network prefixes
106
What type of address does an IPv6 device give itself on start-up?
A link-Local Unicast Address (FE80::Interface ID, address that stays within the network)
107
What type of message does a IPv6 host needt to create its Global Unicast Address (public address)?
The ICMPv6 Router Advertisement
108
How does a IPv6 host receive a ICMPv6 Router Advertisement?
It sends it automatically every 200 secondes
| The Host can ask for one with a ICMPv6 Router Solicitation
109
What router option allows a host to create its own IPv6 address?
SLAAC (Stateless Address Autoconfiguration)
110
What is the first step a web client does to access a web server with a URL?
DNS Lookup
111
What is a socket?
The identifier of all the components that belong in a conversation
112
What does UDP stand for?
User Datagram Protocol
113
What transport layer protocol does an application use when it wants an acknowledgement that the message is delivered?
TCP
114
What transport layer protocol is used when no acknowledgement is needed?
UDP
115
What is an advantage of UDP over TCP?
UDP is faster
116
What type of port is dynamically generated over port number 1024?
The source port
117
What are examples of high level domains?
.com, .edu, .net
118
What happens if a DNS server cannot determine the IP address of a domain name in its DNS table?
The request times out
119
What type of packet is a ping?
ICMP packet (Internet Control Message Protocol)
120
In Windows, hat command shows your default DNS server?
nslookup
121
What is the port number of HTTPS?
443
122
What governs the rules of communication between a web client and a web server?
HTTP (hypertext transfer protocol)
123
To what port does the FTP port 21 change to once the FTP session is open?
20
124
What is one of the oldest Application Layer protocol of the TCP/IP suite?
Telnet
125
What replaced Telnet?
SSH
126
Why is Telnet unsafe?
Information is transferred as plaintext
127
What are the 2 most common home network wireless frequencies?
2.4 GHz and 5 GHz
128
What wireless band is used by Bluetooth?
2.4 GHz
129
What organisation is responsible for the creation of wireless technical standards?
The IEEE
130
What standard governs the WLAN environment?
IEEE 802.11
131
What does SSID stand for?
Service Set Identifier
132
What is the maximum number of characters of an SSID?
32
133
Why are wireless channels used?
To prevent interference of wi-fi networks operating over the same frequency range
134
What is a channel?
A division of the available RF spectrum
135
What is used on Wireless networks to prevent collision during transmission?
Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
Creates a reservation on a channel for a specific conversation
136
What are the 4 steps of the channel reservation process?
- Device sends a Request to Send (RTS)
- If channel available, AP responds with a Clear to Send (CTS) broadcasted on the channel, so all devices know that the channel is busy
- Device transmits data
- Device sends and Acknowledgement (ACK) to the AP to free the channel
137
What does DSL stand for?
Digital Subscriber Line
138
What are the three types of wireless authentication methods?
Open authentication
PSK
EAP
139
What is the encryption method of WPA2 on home networks?
PSK
140
What is one of the easiest way hackers gain access to networks?
Social Engineering
141
What are the 2 types of DoS attacks?
SYN (synchronous) Flooding
| Ping of death
142
What does RPS stand for?
Redundant power system
143
What port is used to configure a switch?
Console port
144
What type of network device management requires a computer to be directly connected to the console port?
Out-of-band management
145
What type of network device management can be done over a network connection?
In-band management
146
What does IOS stand for?
Internetwork Operating System
147
How do you activate priviledged exec mode on the IOS CLI?
Type enable
148
How do you know if you're privileged on the IOS CLI?
The hashtag means you are privileged
149
How do you access the IOS Help command on the Cisco CLI?
Question mark (?)
150
What IOS CLI command is used to get information?
show + argument
151
What elements are usually configured on a LAN switch?
host name
management IP address information
passwords
descriptive information
152
What are the Telnet and SSH connections to a networking device called?
vty lines
153
What does ipconfig do?
Displays IP configuration information
154
What does netstat do?
Displays network connections
155
What does tracert do?
Displays the route taken to a destination
156
What does nslookup do?
Queries the DNS server for information on a destination domain
