System Administration

Important Note -

replace ${user} with your name

replace ${ip} with your ip

While performing execution commands

Example -

var name=rahul;
console.log(`i am ${name}`) //i am rahul
var ip=x;
console.log(`my ip is ${ip}`) //my ip is x

'my name is $ {user}' is equal to 'my name is rahul' in my case so just change it accordingly and same with $ {ip}

And one more important setting you need to make before performing practicals, set your network connection type to bridged type, that is mandatory.

If you are performing practicals on your laptop it might not support “bridged” in that case you need to select “internal” at the bottom

---

Check IP

ip a

Ubuntu Firewall

sudo ufw status 
sudo ufw enable
sudo ufw status

Install & config SSH

sudo apt-get update
sudo apt install openssh-server
sudo ufw allow ssh
sudo systemctl start ssh
sudo systemctl status ssh

Ctrl+c

sudo adduser ${user}

Install putty on windows, open it put your ip and select ssh and run it.

Done!

---

Install & Config Telnet

“xinetd” is server and “telnet” is client so we first need to install xinetd

sudo apt install telnetd xinetd
sudo ufw allow 23
sudo nano /etc/xinetd.d/telnet

File will open up, navigate using arrow keys and add following lines

service telnet
{
 disable = no
 flags = REUSE
 socket_type = stream
 wait = no
 user = root
 server = /usr/sbin/in.telnetd
 log_on_failure += USERID
}
  

Ctrl+s

Ctrl+x

sudo systemctl start xinetd.service
sudo systemctl status xinetd.service

Install putty on windows, open it put your ip and select telnet and run it.

Done!

---

Install FTP Server

sudo apt install vsftpd
sudo ufw allow OpenSSH
sudo ufw allow 20/tcp
sudo ufw allow 21/tcp
sudo ufw allow 990/tcp
sudo ufw allow 40000:50000/tcp
sudo ufw status
sudo nano /etc/vsftpd.conf

Now file will open up, just add the following line at the bottom (so that it can allow upload as well)

write_enable=YES

Ctrl+s

Ctrl+x

Now add user using following command

sudo adduser ${user}

Now open CMD in client machine and type following

ftp ${ip}

Perform login and it will open up so basically done!

Put, Get FTP

Create any name file but I name it test.txt in ubuntu and save at location “home/${user}/”, basically after doing that come back to cmd where ftp is open and write following command

cd /home/${user}
get test.txt
put test.txt

Basically done!

---

Samba Server

sudo apt -y install samba 
sudo ufw allow 'Samba'
mkdir /home/${user}/public/
mkdir /home/${user}/private/
sudo nano /etc/samba/smb.conf

File will open up just go at the end, and add following lines

[public]
  comment = public 
  path = /home/${user}/public 
  read only = no
  browseable = yes 
  guest ok = yes
[private]
  comment = private 
  path = /home/${user}/private 
  read only = no
  browseable = yes 
  guest ok = no

Ctrl+s

Ctrl+x

sudo service smbd start
sudo smbpasswd -a ${user}
sudo service smbd status 

Now it's done, you can check it by simply entering address in this format in the add network location in file explorer at network.

//${ip}/

---

Install HTTP Server

sudo apt-get update
sudo apt-get install apache2
sudo ufw allow 'Apache'
sudo systemctl start apache2.service
sudo systemctl status apache2.service

Now go to windows browser and enter your ubuntu ip, and if it loads Apache page, everything working perfectly fine!

---

Squid Proxy Server

sudo apt install squid
sudo ufw allow 3128
sudo nano /etc/squid/squid.conf

Now pay attention, by default it will deny all http access so you need to navigate to “http_access deny all” and make it “http_access allow all” additionally you need to add two more line at the top as follows

acl blocked dstdomain "/etc/squid/blocked.txt"
http_access deny blocked

Ctrl+s

Ctrl+x

cd /etc/squid/
sudo touch blocked.txt
sudo nano blocked.txt

File will open up, now add urls like

www.facebook.com
www.twitter.com

Ctrl+s

Ctrl+x

sudo systemctl start squid
sudo systemctl enable squid
sudo systemctl status squid

Now it's done! Just change the proxy server in your client as your ubuntu ip and port as 3128

---

therahuldange