Network Addressing Tools

Question 1

What is the official short description of the socket library ?

Answer 1

low-level networking interface

Question 2

The socket library is built on what? used in what systems?

What extra does it provide?

Answer 2

the famous C socket library
used in UNIX systems

higher-level interface and provides more convenient tools

Question 3

The contents of the socket library can be categorized into the following five groups:

Answer 3

Socket Objects
Socket Families
Socket Exceptions

Networking constants
Networking Tools

Question 4

What does the socket object category define

Answer 4

the socket class alongside various methods that are available for socket objects.

The methods are generic and can be applied to client and server sockets

Question 5

What does socket families category define?

Answer 5

defines various ways to represent socket addresses on different platforms using various protocols.

Question 6

What does networking tools category define

Answer 6

a rich list of functions to perform various networking operations

Question 7

what operations can be found in Networking Tools

Answer 7

Address resolution
Network data representation
Getting values of network configuration parameters

Question 8

Define a hostname

Answer 8

a label (string) given to a specific device so it can be identified within a network.

Question 9

Define a domain name

Answer 9

if a device is to be identified on the internet then it has to register the name to ensure that it is unique

Question 10

machine1.secuirty-lab

Answer 10

machine1 is the hostname
security-lab is domain name

Question 11

What is a fully qualified domain name?

Answer 11

Domain name that is completely specified, including all levels

mail.psut.edu

mail is hostname
psut is domain name
edu is higher-level internet domain

Question 12

Every domain name is associated with an IP address
The address resolution happens
through the what protocol?

Answer 12

DNS

Question 13

Can a specific host have multiple hostnames or domain names mapped to the same IP address

Answer 13

Yes
like a web server having an old and a new domain name.

one is considered the hostname and the others are aliases

Question 14

How to get the local hostname

Answer 14

socket.gethostname()

returns a string representing the hostname (not fully qualified domain name)

Question 15

How to get hostname on windows cmd

Answer 15

hostname

Question 16

How to resolve a hostname into an IP address

Answer 16

socket.gethostbyname(hostname)

it returns a four-dot string representing the IPv4 address of the given hostname

if hostname is ‘localhost’ it returns 127.0.0.1 (the loopback IP) special IP address that always points to your own machine.

Question 17

Does gethostbyname method work for IPv4 and IPv6?

Answer 17

nope only ipv4

Question 18

In Windows cmd, you can resolve a hostname into an IPv4 address using:

Answer 18

ping -4 <hostname></hostname>

nslookup <hostname></hostname>

Question 19

It is common to have multiple IPs mapped with a hostname

how to get all of them?

Answer 19

socket.gethostbyname_ex(hostname)

returns a tuple (p_hostname, aliaslist, iplist)

Question 20

does gethostbyname_ex support both ipv4 and ipv6

Answer 20

nope only ipv4

Question 21

what command to run on cmd to get all the IPs ??

Answer 21

ipconfig

Question 22

If I have the IP, how can I resolve it to its hostname

Answer 22

socket.gethostbyaddr(ip_addr)

returns a tuple (p_hostname, aliaslist, iplist)

Question 23

The output is the same for gethostbyaddr() and gethostbyname_ex()

how can they differ

Answer 23

gethostbyaddr() supports both ipv4 and ipv6

gethostbyname() only supports ipv4

Question 24

You can perform reverse DNS through Windows cmd using

Answer 24

nslookup ip

Question 25

How can we get a fully qualified domain name

Answer 25

socket.getfqdn([name]) [name] is optional, if unsepcified it returns localhost fqdn if name is specified, the funtion internally invokes the function gethostbyaddr()

Question 26

Note on a Windows cmd, you can get the fqdn using the command:

Answer 26

whoami fgdn need be domain user

Question 27

How to check if the local machine supports IPv6

Answer 27

socket.has_ipv6 an attribute not a method

Question 28

Get-NetAdapterBinding -ComponentID ms_tcpip62 what does this do?

Answer 28

to check if IPv6 is supported in your machine through Windows PowerShell

Question 29

What are services

Answer 29

Network applications running on a machine each network service is attached to a specific port

Question 30

which port number is attached to 'http'

Answer 30

80

Question 31

which port number is attached to 'smtp'

Answer 31

25

Question 32

To resolve a service name to its corresponding port, we can use the following function:

Answer 32

socket.getservbyname(service_name, [protocol_name]) service name like 'http' 'snmp' 'smtp' protocol is optional, tcp or udp function returns an integer the port number

Question 33

If the service name resolution fails, what exception do we get?

Answer 33

OSError

Question 34

snmp port number

Answer 34

161

Question 35

ftp port number

Answer 35

21

Question 36

To convert a port number to the corresponding service, the following function can be used:

Answer 36

socket.getservbyport(port, [protocol_name])

Question 37

In Windows machines, you can check the status of running network services along with their corresponding ports using

Answer 37

netstat command

Question 38

How to change the hostname?

Answer 38

socket.sethostname(hostname) only in UNIX machines but not on windows, MacOS or Android It requires the user/program to have the right privileges to be executed successfully. If it fails, it raises an OSError.

Question 39

How to get the protocol number from the protocol name

Answer 39

socket.getprotobyname(protoname) Layer 3 and 4 protocols are referred to by the OS using unique integers (defined as constants) in underlying libs

Question 40

protocol numbers for tcp udp icmp ip

Answer 40

6 17 7 0 needed for creating raw sockets