PPT 1: Firewalls, Intro highlighted text

Question 1

This OSI layer defines how two devices should encode, encrypt, and compress data so that it is received correctly on the other end

Answer 1

Presentation layer (L6)

Question 2

This layer is responsible for flow control and error control

Answer 2

Transport layer (L4)

Question 3

This layer is responsible for end-to-end communication between two devices. On the sender end, L_ takes data from the session layer and breaks data up into ________

Answer 3

4 (Transport); segments

Question 4

This layer breaks up segments into packets and reassembles the packets on the receiving end.

Answer 4

Network layer (L3)

Question 5

This layer routes packets by discovering the best path across a physical network

Answer 5

Network layer L3)

Question 6

This layer performs error checking

Answer 6

Data Link layer (L2)

Question 7

This layer is responsible for Media Access Control (MAC) which uses MAC addresses to connect devices and define permissions to transmit and receive data

Answer 7

Data Link layer (L2)

Question 8

This layer is responsible for bit rate control

Answer 8

Physical layer (L1)

Question 9

Name this: These protocols do not establish a
connection between devices. As
soon as a device has data to send
to another, it just sends it

Answer 9

Connectionless Protocol

Question 10

Name this: These protocols require that a
logical connection be established
between two devices before
transferring data.

Answer 10

Connection-oriented

Question 11

ICMP Error codes RFC 792
0 = ?
1 = ?
2= ?

Answer 11

0 = net unreachable
1 = host unreachable
2 = protocol unreachable

Question 12

ICMP Error codes RFC 792
3 = ?
4 = ?
5 = ?

Answer 12

3 = port unreachable
4 = fragmentation needed and DF is set
5 = source route failed