Linux Operating System

Question 1

What is the first process started by Kernal called?

Answer 1

init

Question 2

What are processes launched by init called?

Answer 2

child processes

Question 3

where is the init process typically stored?

Answer 3

/sbin/init

Question 4

PID

Answer 4

process ID - lots of processes rely on PID

Question 5

PPID

Answer 5

Parent process id

Question 6

what is generally used to search for processes?

Answer 6

top and ps

Question 7

free command

Answer 7

frees memory from processes

Question 8

ps -u user –forest does what

Answer 8

shows a tree of processes by the user user

Question 9

ps aux is?

Answer 9

good and adds a user and just makes it look nice? idk 5 this

Question 10

/lib

Answer 10

dynamic libraries and also supports static files needed for the boot process.

Question 11

/usr/lib

Answer 11

also dynamic libraries and support static files for the /usr/bin and /usr/sbin

Question 12

/var/log

Answer 12

logging!

Question 13

/etc

Answer 13

usually contain teh configuration files for all the programs that run on linux/unix

Question 14

Where are deamons’ config files stored

Answer 14

in a subdir of /etc

Question 15

7 layers of internet communcation?

Answer 15

7Application
6Presentation
5Session
4Transport
3Network
2Data link
1Physical

Question 16

1Physical

Answer 16

literally transmits electrical signals between the hosts. It’s the network card connected to a wire

Question 17

2Data Link

Answer 17

defines rules for accessing physical layer. Specifies how to verify data recieved from the physical layer.

Question 18

3Network

Answer 18

Enables routing of data, spefices how to recognize addresses and the next network point to send a node.

Internet and ICMP operate on this level

Question 19

4Transport

Answer 19

sending host’s 4 recieves data and divides it into packets. The receiving provides error checking and unpacks packets and assembles the data.

Question 20

5Session

Answer 20

Responsible for establishing and maintaining a connection between two machienes

Question 21

6Presentation

Answer 21

Ensures information passingthroughout all layers is formatted corretly for 7

Question 22

7Application

Answer 22

provides applications for a way to access networiking

Question 23

TCP

Answer 23

a protocal that ensures data exchanged between two network hosts is exchanged reliably

Question 24

what two protocals are used with IP

Answer 24

TCP and UDP

Question 25

ICMP stands for?

Answer 25

Internet Control Message Protocol.

Question 26

ICMP is used for what?

Answer 26

Testing connections between hosts

Question 27

what layers are ports accessed at

Answer 27

The 4Transport layer

Question 28

20 21

Answer 28

FTP

Question 29

23

Answer 29

Telnet

Question 30

25

Answer 30

SMTP

Question 31

80

Answer 31

HTTP

Question 32

443

Answer 32

HTTPS

Question 33

110

Answer 33

POP3

Question 34

137 138 139

Answer 34

NetBIOS

Question 35

Well-know ports

Answer 35

0-1023

For well established services

Question 36

Registered ports

Answer 36

1024-49151
Special Implementation
Orgs can apply for a reg port number to be assigned to their service

Question 37

Dynamic Ports

Answer 37

49152-65535
Available for any use by any network service
usually used for temporarilly establish connections between two applications.

Question 38

what layer does the MAC address oprate

Answer 38

2Data Link.

MAC address is hardcoded on the network board and cannot be changed.

Question 39

If the last octet in an IP address is 0, what does that mean?

Answer 39

it is the network address. Eg 161.161.161.0. A host cannot use that IP address

Question 40

what is the last octet of 255 reserved for

Answer 40

broadcast addresses.

Question 41

Class A private IP range?

Answer 41

10.0.0.0 - 10.255.255.255

Question 42

Class B private IP range?

Answer 42

172.16.0.0 - 172.31.255.255

Question 43

Class C private IP range?

Answer 43

192.168.0.0 - 192.168.255.255

Question 44

what are the two parts of an ipv4 addr?

Answer 44

Network and node(host)

network is first 3, node is final one