OA Test Review Flashcards
1
Q
OSI Application Layer Function
A
interacts with end users
2
Q
OSI Presentation Layer Function
A
formats the data so it can be viewed by the user
3
Q
OSI Session Layer Function
A
establishes and ends connections between 2 hosts
4
Q
OSI Transport Layer Function
A
breaks data into packets and transmits them over networks. Flow control and error checking
5
Q
OSI Network Layer Function
A
reads the IP address from the packet
6
Q
OSI Data Link Layer Function
A
transmits info on computers connected to the same LAN. Reads the MAC address on the packet
7
Q
OSI Physical Layer Function
A
translates binary into the language of the transport medium
8
Q
TCPIP Application layer function
A
interacts with apps that need to gain access to network services
9
Q
TCPIP host to host/transport layer function
A
segments data and validates it hasn’t been corrupted
10
Q
TCPIP network/internet layer function
A
routing of packets as they move around the network
11
Q
TCPIP physical layer function
A
protocols interface with medium
12
Q
Layer Devices
7. application
6. presentation
5. session
4. transport
3. network
2.data link
1. physical
A
- gateway, firewall, endpoint device
- gateway, firewall, server, PC
- gateway, firewall, server, PC
- gateway, firewall
- router, brouter, layer 3 switch
- bridge modem, network card, layer 2 switch
- hub, repeater, cable, fiber, wireless
13
Q
TCPIP Layer Protocols
4. application
3. host to host/transport
2. network/internet
1. physical
A
- telnet, smtp, ftp, http
- TCP, UDP
- IP, ICMP, ARP, DHCP
- ethernet, PPP, ADSL
14
Q
TCPIP Application Layer Function
A
interacts with apps that need to gain access to network services
15
Q
TCPIP Host to Host/transport Layer Function
A
segments data and validates it hasn’t been corrupted
16
Q
TCPIP Network or internet layer function
A
routing of packets as they move around the network
17
Q
Physical or Network access layer function
A
high layer protocols interface with transport mediums
18
Q
Attenuation
A
signal loss on transmission media
19
Q
hub
A
hardware device with ports for multiple connections that echoes every message it receives to ALL connected ports
20
Q
switch
A
device with multiple ports but examines the message and knows which port it should forward the message to. allows multiple devices to communicate
21
Q
host based network
A
central computer/main frame with many users that connect directly to it using terminals such as keyboard and monitor
22
Q
client server internetworking
A
central server handles data and local client software on client devices that requests services from server
23
Q
peer to peer internetworking
A
use of an enterprise network for peers to exchange messages without depending on a central server to manage connections and messages
24
Q
bridge
A
device needed for internetworking at the data link layer. listens to received traffic and remembers ports on which the traffic arrived from each MAC address. interconnects 2 or more LANs
25
router
forward IP packets based on where that IP network is physically located and the physical port or interface that connects to it
26
NIC network interface controller
allows device to connect and communicate on the network
27
prevention broadcast stormed caused by loops
uses RSTP or MSTP to stop packets from traveling in a circle and never reaching a destination
28
VLAN
used in flat topology where there is no hierarchy to the network structure.
29
circuit switched
a network that creates a path between a source and destination device
30
extranet
private network that allows authorized external users to securely share info
31
internet protocol IP
part of TCPIP that makes it possible to deliver packets across complicated networks by handling routing decisions
32
internetworking
the process of connecting multiple computer networks
33
intranet
private internal network
34
logical topology
shows how the devices in a network connect to a specific segment of the network
35
OSI Reference Model
internationally accepted framework of standards that governs how separate computer systems communicate using networks
36
packet switched
networks that transmit packets as individual messages
37
physical topology
physical network devices and any physical devices used to connect to the network
38
point to point network
network that consists only of computers and devices that are connected directly
39
TCP
part of the TCPIP that guarantees a reliable stream of data between two computers
40
TCPIP Reference Model
descriptive framework for computer network protocols created by DoD in the 70s
41
TCPIP Suite
a collection that provides support to nearly all internet capable operation systems and devices
42
TCPIP Data Link sublayer- logical link layer LLC
top layer that talks directly to the network layer and provides error control
43
TCPIP Data link sublayer- media access control layer
talks to the physical layer and defines how frames are placed on the wire
44
well known ports
0-1023
45
registered ports
1024-49151
46
dynamic ports
49151-65535
47
3 way handshake
syn (synchronize), syn/ack, ack (acknowledge)
48
bit
binary digit
49
nibble
collection of 4 bits (half a byte or half an octet)
50
byte
number of bits a system has used to encode one text character. 8 bits.
51
IPv4 IP address length
32 bits= 4 bytes= 4 octets
52
IPv6 IP address length
8 groups of 4 hexdigits, each group of 4 hexdigits= 16 bits, so 128 bits
53
IPv6 IP address set up
first 48 bits=network
next 16 bits=subnet ID
last 64 bits= client ID
54
T568A wire
starts with green, residential
55
T568B wire
starts with orange, commercial
56
Class A address Subnet Mast
255.0.0.0
57
Class B address subnet mask
255.255.0.0
58
class c address subnet mask
255.255.255.0
59
reliability
availability and integrity of the data transmission
60
uptime
whether there is a physical link access to the communication line
61
integrity
whether the data made it to the destination intact and accurate
62
6 components of a structured wiring system
1. building cabling entrance
2. data center/equipment room
3. backbone cabling
4. telecom room/wiring closet
5. horizontal cabling
6. workstation/office location
63
attenuation
measure amount of signal loss at the other end
64
crosstalk
where a signal on one pair of twisted cables interferes with another pair
65
propagation delay
amount of time it takes for signal to reach the end of the cable
66
return loss
measures signal reflections that are caused by an impedance mismatch from end to end
67
802.3
ethernet standards
68
CSMA/CD carrier sense
NIC cards listen on the physical media for specific voltage levels or carrier signals. if coast is clear, NIC can transmit
69
CSMA/CD multiple access
NIC cards can transmit simultaneously. when this happens, a collision is noticed by the NIC card transceivers
70
CSMA/CD collision detection
NIC cards react to signal collisions by retransmitting after receiving a notification that a collision occurred
71
Multilayer hierarchal backbone
each departmental LAN connects to a common chassis based high speed backbone. traffic bound for other departments and workgroups, must be sent to the department's router
72
flat backbone
each departmental LAN connects to a common chassis based high speed backbone. traffic bound for departmental LANs is layer 2 switched via VLANs and ethernet tagging to direct traffic between departmental LAN locations
73
collapsed backbone
aka backbone in a box or inverted backbone.
74
data link layer- aka
protocol layer
75
ethernet
wired system for connecting devices in a LAN, MAN, and WAN
76
protocol
established set of rules to determine how data can be transmitted across devices
77
redundancy
process of providing alternate means for a network to continue functioning
78
repeater
device that receives and amplifies a signal
79
resilience
ability to continue providing acceptable service despite operations challenges
80
protocols operating at network layer/layer 3
IP, ICMP, IPSec, appletalk
81
protocols operating at transport layer/layer 4
TCP and UDP
82
tranport layer/layer 4 services provided
flow control
fragmentation and reassembly
error control
acknowledgement of delivery
83
addressing
identifies source and destination host
84
IPv6 provides the following services
version
traffic class
flow label
addressing
85
how application layer refers to data
APDU: application protocol data unit
86
how presentation layer refers to data
PPDU: presentation protocol data unit
87
how session layer refers to data
SPDU: session protocol data unit
88
how transport layer refers to data
segment or datagram
89
how network layer refers to data
packet
90
how data link layer refers to data
frame
91
how physical layer refers to data
bits
92
MAC address
hardware address on TCPIP host that never changes
93
MAC address length
48 bits
94
MAC address set up
first half is OUI
second half is vendor assigned
95
IPv4 loopback address
127.0.0.1
96
SLAAC
stateless address autoconfig
autogenerates a link local address
loopback address starts with ::1
97
unicast network methodology
sending a packet to a single destination
98
anycast network methodology
sending a packet to the nearest node in a specified group of nodes
99
multicast network methodology
sending a packet to multiple destination
100
types of connectionless communication
UDP, ICMP, DNS, TFTP, SNMP
101
connection oriented protocol
sets up a connection between the source and destination
102
connectionless protocol
treats each connection individually
103
datagram
packets that are transmitted across networks
104
IANA
oversees all allocations of IP addresses
105
NAT
maps local private addresses to public ones
106
full duplex mode of communication
both ends of communication communicate simultaneously
107
half duplex mode of communication
both ends can communicate but 1 at a time
108
simplex mode of communication
source only sends data to a destination and destination cannot respond
109
common layer 5 (session layer) protocols
H.254
L2TP
NetBIOS
RPC
SMB
SOCKS
110
common layer 6 (presentation layer) protocols
IMAP
SSH
SSL
TSL
111
common file formats for layer 6/presentation
JPEG, GIF, TIFF, MPEG, MIDI
112
application layer software steps
1. accepts some messages as input from application software and adds any additional data such as address of target computer
2. calls other software from the next lower layer and sends a new messages (original + new data)
3. may chop the message into smaller chunks before sending each chunk to the next layer
4. then may wait for a reply
113
common protocols at layer 7/application
DHCP
HTTP
FTP
RTP
SIP
telnet
SMTP
SNMP
114
FTP port
20/21
115
SSH and SFTP port
22
116
telnet port
23
117
smtp port
25
118
DNS port
53
119
DHCP port
67/68
120
http port
80
121
HTTPS port
443
122
host based application
everything runs off the central host with dumb terminal devices
123
client based application
data storage function stayed on central server but everything else on client BAD IDEA
124
client server application
computing split the data and processing tasks into 2 main partitions- server handles data while clients handle the processing
125
cloud computing/n-tier application
appserver is a program that runs on a central server that handles processing logic. appserver is colocated with database server. once it finished processing, it only sends results over the network to the client
126
peer to peer applications
peers share data and processing with each other.
127
malware examples
trojan horse
spyware
virus
worm
ransomware
DoS attack
DDoS
botnets
128
arpanet
a computer network developed by the DoD to support academic research
129
layer 2 tunneling protocol
protocol that supports VPNs
130
web browser
protocol to allow all resources to be linked together
131
class A private IP addresses
10.0.0.0- 10.255.255.255
132
class b private IP address
172.16.0.0- 172.31.255.255
133
class c private IP address
192.168.0.0- 192.168.255.255
134
internetwork with a gateway
connects networks that use different protocols by translating packets to protocol compatible with destination
135
lowest cost of connectivity
high port density
136
first packet switched network
arpanet
137
broadcast MAC address
ff:ff:ff:ff:ff:ff
138
patch panel
keeps a large number of cables organized. connect patch cable from workstation to panel to layer 2/layer 3 switch
139
ICMP
core protocol on IP suite. provides easy method to send short messages. most commonly used for error messages
140
UDP
best effort, but no guarantee. treats each packet individually
141
IDS
intrusion detection system. passive, only alerts
142
IPS
intrusion prevention system. takes action to decide whether to accept or reject packets based on rules
143
vampire tap
bites into thicknet to connect individual machines to ethernet
144
media converter
allows you to integrate new equipment into existing cabling infrastructure
145
most common topology in early ethernet
bus
146
real time apps benefit from _______
layer 2 switch
147
router runs on which layer
network layer
148
which class has the fewest nodes in each network
class c
149
/24 subnet mask is how many bits
8 bits
150
NDP: IPv6 as ____: IPv4
ARP
151
technical safeguards
VLAN segmentation, workstation hardening, redundant network connections
152
network with lowest TCO
IP based
153
basic topology for FDDI
ring
154
what devices supplies PoE
layer 3 switch
155
access control list
rules governing stateless firewalls to control flow of traffic
156
what layer does IPSec work
layer 3
157
port listening on a server set up to automatically assign IP addresses
UDP 67
158
usability
ability of different parts of network to work together
159
insecure ports
20, 21, 23, 80
160
ethernet collision domain
special area created by each port on full duplex layer 2 switch
161
flood guard
security feature on some switches that blocks some unwanted broadcast messages
162
number of individual usable VLANs allowed by VLAN field
4094
163
convergence
all routers are synchronized
164
IEEE standards for token ring
802.5
165
Cut through switching
Forwards as soon as it reads the destination address
166
aggregation of edge networks is a
collapsed backbone
167
edge network
desktop workstation LAN connection
168
architecture in which all processing functions are on the client
P2P
169
kerberos port
88
170
BGP port
179
171
SaaS
software applications hosted by vendor. often used through web browser
172
PaaS
cloud provides an environment for client to build and use their own software
173
IaaS
cloud provides network access to traditional computing resources such as processing power and storage.
