10.install-and-setup-ufw-firewall.md

How to Setup and Config UFW on VPS

What is Firewall ?

A firewall is computer hardware or software that controls inbound and outbound traffic of a machine.

What is UFW ?

UFW (Uncomplicated Firewall) is presented as a front-end of Iptables. By default, UFW denies all incoming connections and allows all outgoing connections.

• Install UFW

  apt install ufw

• Check UFW Status

  • To Check Normal Mode

    ufw status

  • To Check in more Comprehensive

    ufw status verbose

  • To Check with Number

    ufw status numbered

• Enable UFW

  ufw enable

  • Note command may disrupt existing ssh connections. Proceed with operation. we need to allow ssh service

    ufw allow ssh

• Disable UFW

  ufw enable

• Configure to support IPv6

  • Open Config File

    nano /etc/default/ufw

  • then Change: IPV6=yes

• To Restart Firewall Disable it then Enable it

  ufw disable;
  ufw enable

• To Check Open Port, It will show only those which are currently running

  netstat -tulpn

• To Open Port

  • Syntax -

    ufw allow <port/protocol>

  • Example -

    ufw allow 21/tcp

• To Close Port

  • Syntax -

    ufw deny <port/protocol>

  • Example -

    ufw deny 21/tcp

• To Open a Range of Ports

  • Syntax -

    ufw allow [Starting_port:Ending_port]/protocol

  • Example -

    ufw allow 300:310/tcp

• To Close a Range of Ports

  • Syntax -

    ufw deny [Starting_port:Ending_port]/protocol

  • Example -

    ufw deny 300:310/tcp

• To Allow Service

  • Syntax -

    ufw allow <service_name>

  • Example -

    ufw allow http

• To Deny Service

  • Syntax -

    ufw deny <service_name>

  • Example -

    ufw deny http

• To Allow Access to IP Address

  • Syntax -

    ufw allow from <IPAddress>

  • Example -

    ufw allow from 192.168.1.4

• To Deny Access to IP Address

  • Syntax -

    ufw deny from <IPAddress>

  • Example -

    ufw deny from 192.168.1.4

• To Allow IP to connect only specific Port

  • Syntax -

    ufw allow from <IPAdress> to any port Port

  • Example -

    ufw allow from 192.168.1.4 to any port 45

• To Delete a Specific Rule

  1. Check Status with Number

     ufw status numbered

  2. Delete with Number

     • Syntax -

       ufw delete <number>

     • Example -

       ufw delete 3

• To Reset to Default Setting

  ufw reset

• Some useful connection which You may want to allow

  1. To Allow SSH Connection

     ufw allow ssh

     Or

     ufw allow 22/tcp

  2. To Secure Web Server

     ufw allow 80/tcp

  3. To Allow FTP Connection

      ufw allow ftp

     Or

     ufw allow 21/tcp; 
     ufw allow 20/ftp

  4. To Allow Web Server Profile(http)

     ufw allow www

  5. To Allow https

     ufw allow https

Reference Doc Links

• YouTube Video Link

• Ubuntu Community Link