ITI

A router receives an IP packet where the header contains TTL=1. What will the router do with this IP packet? (IPv4)

A router has to fragment an IP packet for further transmission. The IP header contains the flags MF=0 and DF=1. What will the router do with this IP packet? (IPv4)

What is the purpose of the Identification field in the IP header? (IPv4)

Consider the following set of DNS records:

www.site1.tld. 86400 IN A 106.244.0.1 
www.site2.tld. 86400 IN A 106.244.0.1 
www.site3.tld. 86400 IN A 106.244.0.1

Which conclusion(s) could be drawn?

A single Apache web server installation shall be used to serve 99 different web sites via IPv4 on the well-known port 80.

How many IPv4 addresses are at least required when using name-based virtual hosts only?

A single Apache web server installation shall be used to serve 99 different web sites via IPv4 on the well-known port 80.

How many IPv4 addresses are at least required when using IP-based virtual hosts only?

Consider an Apache web server installation where two virtual hosts are defined:

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site1.tld 
  DocumentRoot /var/www/x 
  <Directory /var/www/x> 
    Options -Indexes 
    Require ip 199.232.0.0/18 
    Require ip 199.232.128.0/17 
  </Directory> 
</VirtualHost>

-------------------------------------------------------------------------------

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site2.tld 
  DocumentRoot /var/www/y 
  <Directory /var/www/y> 
    Options -Indexes 
    <RequireAll> 
      Require all granted 
      Require not ip 199.234.0.0/15 
    </RequireAll> 
  </Directory> 
</VirtualHost>

where everything (Apache, DNS, network) is configured correctly such that these virtual hosts are reachable. The Apache directive DirectoryIndex is left at its default value and the following files exist below the directory /var/www:

/var/www/x/file1 
/var/www/x/index.html 
/var/www/y/file1

What is returned to the client PC with IP address 199.232.0.1 for the request URL: http://www.site1.tld/

Consider an Apache web server installation where two virtual hosts are defined:

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site1.tld 
  DocumentRoot /var/www/x 
  <Directory /var/www/x> 
    Options -Indexes 
    Require ip 199.232.0.0/18 
    Require ip 199.232.128.0/17 
  </Directory> 
</VirtualHost>

-------------------------------------------------------------------------------

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site2.tld 
  DocumentRoot /var/www/y 
  <Directory /var/www/y> 
    Options -Indexes 
    <RequireAll> 
      Require all granted 
      Require not ip 199.234.0.0/15 
    </RequireAll> 
  </Directory> 
</VirtualHost>

where everything (Apache, DNS, network) is configured correctly such that these virtual hosts are reachable. The Apache directive DirectoryIndex is left at its default value and the following files exist below the directory /var/www:

/var/www/x/file1 
/var/www/x/index.html 
/var/www/y/file1

What is returned to the client PC with IP address 199.232.0.1 for the request URL: http://www.site1.tld/

Consider an Apache web server installation where two virtual hosts are defined:

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site1.tld 
  DocumentRoot /var/www/x 
  <Directory /var/www/x> 
    Options -Indexes 
    Require ip 199.232.0.0/18 
    Require ip 199.232.128.0/17 
  </Directory> 
</VirtualHost>

-------------------------------------------------------------------------------

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site2.tld 
  DocumentRoot /var/www/y 
  <Directory /var/www/y> 
    Options -Indexes 
    <RequireAll> 
      Require all granted 
      Require not ip 199.234.0.0/15 
    </RequireAll> 
  </Directory> 
</VirtualHost>

where everything (Apache, DNS, network) is configured correctly such that these virtual hosts are reachable. The Apache directive DirectoryIndex is left at its default value and the following files exist below the directory /var/www:

/var/www/x/file1 
/var/www/x/index.html 
/var/www/y/file1

What is returned to the client PC with IP address 199.232.64.1 for the request URL: http://www.site2.tld/

Consider an Apache web server installation where two virtual hosts are defined:

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site1.tld 
  DocumentRoot /var/www/x 
  <Directory /var/www/x> 
    Options -Indexes 
    Require ip 199.232.0.0/18 
    Require ip 199.232.128.0/17 
  </Directory> 
</VirtualHost>

-------------------------------------------------------------------------------

<VirtualHost *:80> 
  ServerAdmin [email protected] 
  ServerName www.site2.tld 
  DocumentRoot /var/www/y 
  <Directory /var/www/y> 
    Options -Indexes 
    <RequireAll> 
      Require all granted 
      Require not ip 199.234.0.0/15 
    </RequireAll> 
  </Directory> 
</VirtualHost>

where everything (Apache, DNS, network) is configured correctly such that these virtual hosts are reachable. The Apache directive DirectoryIndex is left at its default value and the following files exist below the directory /var/www:

/var/www/x/file1 
/var/www/x/index.html 
/var/www/y/file1

What is returned to the client PC with IP address 199.234.0.1 for the request URL: http://www.site2.tld/file1

Working with the bash, the current directory contains 5 files:

   f12   f65   f66179   f9   f96581

How many files are listed for each of the following commands?

ls  ?[5][4]*?

Working with the bash, the current directory contains 5 files:

   f12   f65   f66179   f9   f96581

How many files are listed for each of the following commands?

ls  *[7491]

You enter the following command at the shell prompt and get the resulting output:

seq 84 186 | head -$a | tail -$b 
148

Given the output of the command above, what is the value of the shell variable a?

You enter the following command at the shell prompt and get the resulting output:

seq 84 186 | head -$a | tail -$b 
148

Given the output of the command above, what is the value of the shell variable b?

Working with the bash, the shell variable v has been set to 173 (i.e., v=173). What is the output of the following commands?

echo  "\\$v"

Working with the bash, the shell variable v has been set to 173 (i.e., v=173). What is the output of the following commands?

echo  "'$v'"

The IP address configuration of a network interface is given by: 121.206.139.252/19

Determine the corresponding NETWORK address.

The IP address configuration of a network interface is given by: 121.206.139.252/19

Determine the corresponding BROADCAST address.

The IP address configuration of a network interface is given by: 121.206.139.252/19

Determine the corresponding NETMASK in dotted-decimal notation.

The IP address configuration of a network interface is given by: 121.206.139.252/19

How many computers could be operated in total in that network such that each computer gets one unique IP address?

Working with the bash, you issue the command: "chmod 376 file1". What are the resulting file permissions of file1?

Working with the bash, you want to show the content of files. Which command do you use?

Consider the following shell script named ”myscript”:

#!/bin/bash 
case "$1" in 
      ls|rm) 
            $1 "$0" 
            ;; 
      cp|mv) 
            "$1" "$0" "$2" 
            ;; 
      echo|mkdir) 
            "$2" "$0" "$1" 
            ;; 
      *) 
            "$0" ls 
            ;; 
esac

The current directory just contains the file ”myscript”. Now, the script is called like:

./myscript mkdir cp

When the script is finished, what has happend in the current directory?

Consider the following shell script named ”myscript”:

#!/bin/bash 
case "$1" in 
      ls|rm) 
            $1 "$0" 
            ;; 
      cp|mv) 
            "$1" "$0" "$2" 
            ;; 
      echo|mkdir) 
            "$2" "$0" "$1" 
            ;; 
      *) 
            "$0" ls 
            ;; 
esac

The current directory just contains the file ”myscript”. Now, the script is called like:

./myscript mkdir cp

What is written to STDOUT/STDERR during execution of the script?

Working with the bash, the current directory contains 5 files:

   f12   f65   f66179   f9   f96581

How many files are listed for each of the following commands?

ls  *?*?

Working with the bash, the current directory contains 5 files:

   f12   f65   f66179   f9   f96581

How many files are listed for each of the following commands?

ls  *?[2]

Working with the bash, the current directory contains 5 files:

   f12   f65   f66179   f9   f96581

How many files are listed for each of the following commands?

ls  ?

The file data.csv contains 10 comma-separated values per line, i.e. 10 columns like:

column 1,column 2,column 3,column 4,column 5,column 6,column 7,column 8,column 9,column 10

The following command is issued at the shell prompt:

sed -r 's/([^,]*),([^,]*),[^,]*,([^,]*),[^,]*,[^,]*,([^,]*)$/\1/' < data.csv

Which columns do match the regular expression?

The file data.csv contains 10 comma-separated values per line, i.e. 10 columns like:

column 1,column 2,column 3,column 4,column 5,column 6,column 7,column 8,column 9,column 10

The following command is issued at the shell prompt:

sed -r 's/([^,]*),([^,]*),[^,]*,([^,]*),[^,]*,[^,]*,([^,]*)$/\1/' < data.csv

Which columns are shown in the output?

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

Does this listing show a file or a directory?

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

Which user is the owner of the file/directory? (user name)

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

Which group is associated with the file/directory? (group name)

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

What is the name of the file/directory? (file/directory name)

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

Does the owner have execute permissions?

Working with the bash, the command ls -l shows the following output:

-rwxrwx--- 10 q s 7239 2011-01-01 00:01 n

What is the size of the file/directory?

Consider the following shell script named ”myscript”:

#!/bin/bash 
V="$1" 
if [ $1 -lt 655 ]; then 
      echo $((V + 2)) 
else 
      echo "`ls`" 
fi

The current directory just contains the file ”myscript”. What is shown in the output when the script is called like:

./myscript 577

You enter the following command at the shell prompt:

seq 207 431 | grep 760 && echo 896

What is shown in the output?

Working with the bash, the shell variable v has been set to 173 (i.e., v=173). What is the output of the following commands?

echo  "$v"

Working with the bash, the shell variable v has been set to 173 (i.e., v=173). What is the output of the following commands?

echo  "\$v"