CCNA Chapter 2

Question 1

TCP/IP model layers

Answer 1

Application Layer, Transport Layer, Internet Layer, Link Layer

Question 2

Application Layer

Answer 2

Apps communicate with this layer’s protocols in order to be networked successfully. Commonly used protocols include HTTP(S), FTP, TFTP, Telnet, SSH, and SMTP

Question 3

HTTP

Answer 3

Hypertext transfer Protocol. used for web browsing. HTTPS is its secure version

Question 4

FTP

Answer 4

file transfer protocol. used to transfer computer files from a server to a client.

Question 5

TFTP

Answer 5

trivial file transfer protocol. unsecured version of FTP

Question 6

Telnet/SSH

Answer 6

used to allow someone to remotely connect to a Linux computer to run an application as a virtual terminal. Also allow you to connect to a Cisco switch or router to reconfigure remotely

Question 7

SMTP

Answer 7

Simple mail transport protocol. Used for e-mail.

Question 8

Transport Layer

Answer 8

Two main protocols: TCP and UDP.

Identifies the port number of the application protocol being used and adds that port number to the data

Question 9

TCP

Answer 9

Transmission control protocol.

Ensures the target host is there before sending data (called handshaking). Ensures target host received previous piece of data before sending next piece of data.

Provides sequencing; puts sequence numbers on each piece of data so that if data arrives out of order it can be put back in order

Question 10

UDP

Answer 10

User datagram protocol

no handshaking or sequencing, but faster than TCP

Question 11

Internet Layer

Answer 11

Primary protocol is IP (Internet Protocol).

adds an IP address to the data, part of which is the network segment the workstation is on, and part of which represents the node.

Question 12

Link Layer

Answer 12

often broken into two layers:

Data Link Layer
Physical Layer

Question 13

Data Link Layer

Answer 13

packages the data with physical addresses (MAC addresses) that identify both the card that sent the data and the card which the data is supposed to go to.

Question 14

Functions of the TCP/IP model

Answer 14

Provides a common reference point for network professionals.

Divides networking tasks into logical layers for easier comprehension.

Promotes standards between networks and devices.

Question 15

Limitations of the TCP/IP model

Answer 15

Layers are theoretical and do not actually perform real functions.

Industry implementations rarely have a layer-to-layer correspondence with the TCP/IP layers.

A particular protocol implementation may not represent every layer or may be spread across multiple layers.

Question 16

Well known port numbers in TCP/UDP

Answer 16

TCP:
FTP - Ports 20, 21
HTTP - Port 80
POP3 (Post Office Protocol) - Port 110
NNTP (Network News Transport Protocol) - Port 119
IMAP4 (Internet Message Access Protocol) - Port 143
SNMP (Simple Network Management Protocol) - Ports 161, 162
LDAP (Lightweight Directory Access Protocol) - Port 389
HTTP with SSL(Secure Sockets Layer) - Port 443

UDP:
DHCP (Dynamic Host Configuration Protocol) - Ports 67, 68
TFTP (Trivial File Transfer Protocol) - Port 69
NTP (Network Time Protocol) - Port 123

TCP/UDP:
SSH - Port 22
Telnet - Port 23
SMTP - Port 25
DNS - Port 53