1
What does the Net +
consist of?(percentage)
Networking Fundamentals = 24%
Network Implementations = 19%
Network Operations = 16%
Network Security = 19%
Network Troubleshooting = 22%
2
What is the OSI Model?
Stands for Open Systems Interconnection Model.
Used to describe how traffic moves from one part of
the network to another.
3
Explain layer 1 of the
OSI Model
Layer 1 is the physical part of the OSI model. It includes
cables, connectors. No protocols in this layer.
4
What do you do if you
have a physical layer(
layer 1) problem?
Fix your cabling, punch downs, etc. Run loopback
tests, test(replace cables, swap adapter cards(Wi-Fi
card, etc.)
5
Explain layer 2 of the
OSI Model
Data link layer. Considered the basic network "language".
Foundation of communication at the data link
layer. Considered the "switching" layer.
6
What protocol(s)
does layer 2 use in the
OSI Model?
Data Link Control(DLC) protocol. MAC(Media Access
Control) addresses on ethernet are in this layer
7
Explain layer 3 of the
OSI Model
Called the network layer, also referred to as the routing
layer. Uses IP(Internet Protocol).
8
What protocol(s)
does layer 3 use in the
OSI Model?
Many protocols get used in this layer. Some of these
are IPv4, ICMP, ARP(Address Resolution Protocol),
etc.
9
In what layer does
data get fragmented?
Fragmentation of frames occurs in layer 3(network).
Fragmentation occurs when data travels from different
types of networks. e.g. Data moving from ethernet
to WAN network
10
Explain layer 4 of the
OSI Model
Transport layer. Considered the "post office" layer because
this layer describes how data is being delivered
and where it is being delivered.
11
What protocol(s)
does layer 4 use in the
OSI Model?
Layer 4 uses TCP(Transmission Control Protocol)
and UDP(User Datagram Protocol). Used when you
are accessing a web page but web page's data is so
large that the data can't be sent in one single frame.
Instead, frames will need to be split up and each one
is sent individually. They will be put back together on
the other side.
12
Explain layer 5 of the
OSI Model
Session layer. This layer is designed to start and stop
communication between one endpoint and another.
Also used to combine information that are coming
from different streams and origins. Like a video call
where video and audio need to be synchronized.
13
What protocol(s)
does layer 5 use in the
OSI Model?
Uses control protocols and tunneling protocols in
order to begin communication of data between one
device and another.
14
Explain layer 6 of the
OSI Model
Presentation layer. Takes data and encodes characters
to something we can understand. Encryption of
application data will occur in layer 6 too. Often combined
with layer 7.
15
Explain layer 7 of the
OSI Model
Application layer. Layer that we get to see.
16
What protocol(s)
does layer 7 use in the
OSI Model?
HTTP, FTP, DNS, POP3
17
If you are working
with cables, fiber, and
the signal(bits) itself
what layer are you
working with?
Layer 1 - physical layer
18
If you are working
with frames, MAC
addresses, Extended Unique Identifier(
EUI-48, etc.), and
switch forwarding
what layer are you
working with?
Layer 2 - data link
19
If you are working
with IP addresses,
router, packets what
layer are you working
with?
Layer 3 - network
20
If you are working
with TCP segments
and UDP datagrams,
and the port numbers
associated with TCP
and UDP what layer
are you working
with?
Layer 4 - transport
21
If you are working
with control protocols,
and tunneling
protocols, or setting
up communication
between one
device and another
what are you working
with?
Layer 5 - session
22
If you are working
with
encryption(SSL/TLS)
or communicating
through a web
browser over
HTTPS(443) what
layer are you working
with?
Layer 6 - presentation
23
If you are working
with a web browser
that you are viewing
on your computer
what layer are you
working with?
Layer 7 - application
24
Explain the OSI Model
when accessing
mail.google.com
Physical: Electric signals
Data Link: Ethernet(encapsulates TCP and IP within
ethernet frames)
Network: IP encapsulation
Transport: TCP encapsulation(uses 443 port to send
data)
Session: Links the transport layer to the presentation
layer
Presentation: SSL encryption
Application: https://mail.google.com