{"id":5230,"date":"2024-09-01T22:10:17","date_gmt":"2024-09-01T16:40:17","guid":{"rendered":"https:\/\/www.veeble.org\/kb\/?p=5230"},"modified":"2025-03-14T11:37:06","modified_gmt":"2025-03-14T06:07:06","slug":"how-to-open-a-specific-port-on-linux","status":"publish","type":"post","link":"https:\/\/www.veeble.com\/kb\/how-to-open-a-specific-port-on-linux\/","title":{"rendered":"How to Open a Specific Port on Linux"},"content":{"rendered":"\n
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\"How<\/a><\/figure>\n<\/figure>\n\n\n\n

On a Linux system, opening a specific port is essential for allowing network traffic, running specific services, or enabling applications to communicate with other devices. This short tutorial will walk you through opening a port using UFW (Uncomplicated Firewall)<\/a>, IPtables<\/a>, FirewallD<\/a>, or starting a service. If you are looking for a tutorial to open a port in Linux, please check our tutorial: How to Close a Specific Port on Linux<\/a><\/p>\n\n\n\t\t\t\t

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  1. How to Check Open Ports on Linux<\/a>
  2. How to Open a Port Using UFW (Uncomplicated Firewall)<\/a>
  3. How to Open a Port Using IPtables<\/a>
  4. How to Open a Port Using Firewalld<\/a>
  5. How to Start a Service to Open a Port<\/a>
  6. Simple, Powerful Windows VPS Hosting<\/a><\/ol>\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\n\n\n

    <\/p>\n\n\n

    How to Check Open Ports on Linux<\/h3>\n\n\n

    Before opening a port, it is a good idea to see which ports are already open. You can use one of these commands:<\/p>\n\n\n\n

    Using netstat:<\/strong><\/p>\n\n\n\n

    sudo netstat -tuln<\/pre>\n\n\n\n
    This command lists all the currently open ports. Below is a sample output where the open ports are underlined in red (e.g., 22 and 53).<\/p>\n\n\n\n
    \n
    \"sample<\/a><\/figure>\n<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    Using ss:<\/strong><\/p>\n\n\n\n
    sudo ss -tuln<\/pre>\n\n\n\n
    This command provides similar information to netstat<\/code> and is often preferred for its additional options and efficiency.<\/p>\n\n\n\n
    \n
    \"sample<\/a><\/figure>\n<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    Using lsof:<\/strong><\/p>\n\n\n\n
    The lsof<\/code> command is mostly not preinstalled on Linux systems. You need to manually install this command to use. If you are using a Debian-based system like Ubuntu, use the command: sudo apt-get install lsof<\/code> to install. For Centos\/Redhat: sudo yum install lsof<\/code> and for Fedora: sudo dnf install lsof<\/code><\/pre>\n\n\n\n
    After installing, run:<\/p>\n\n\n\n
    sudo lsof -i -P -n<\/pre>\n\n\n\n
    \n
    \"sample<\/a><\/figure>\n<\/figure>\n\n\n\n
    These commands will list all the open ports on your system, allowing you to verify whether the port you want to open is already open.<\/p>\n\n\n\n
    <\/p>\n\n\n
    How to Open a Port Using UFW (Uncomplicated Firewall)<\/h3>\n\n\n
    For Ubuntu and other Debian-based systems, UFW is a straightforward firewall management application.<\/p>\n\n\n\n
    Install UFW (if it\u2019s not installed):<\/strong><\/p>\n\n\n\n
    sudo apt-get install ufw
    sudo ufw enable<\/pre>\n\n\n\n
    Open the Port:<\/strong><\/p>\n\n\n\n
    Replace <port_number><\/code> with the port number you want to open.<\/p>\n\n\n\n
    sudo ufw allow <port_number><\/pre>\n\n\n\n
    This command will open the specified port. For example, to open port 80:<\/p>\n\n\n\n
    sudo ufw allow 80<\/pre>\n\n\n\n
    \n
    \"open<\/a><\/figure>\n<\/figure>\n\n\n\n
    Check UFW Status:<\/strong><\/p>\n\n\n\n
    sudo ufw status<\/pre>\n\n\n\n
    This command will show the current status of UFW, including which ports are allowed.<\/p>\n\n\n\n
    <\/p>\n\n\n
    How to Open a Port Using IPtables<\/h3>\n\n\n
    IPtables is a powerful tool for controlling firewall rules on Linux.<\/p>\n\n\n\n
    Install IPtables (if not installed):<\/strong><\/p>\n\n\n\n
    sudo apt-get install iptables<\/pre>\n\n\n\n
    Allow the Port:<\/strong><\/p>\n\n\n\n
    Replace <port_number><\/code> with the port number you want to open.<\/p>\n\n\n\n
    sudo iptables -A INPUT -p tcp --dport <port_number> -j ACCEPT
    sudo iptables -A INPUT -p udp --dport <port_number> -j ACCEPT<\/pre>\n\n\n\n
    This command will open the specified port for both TCP and UDP protocols. For example, to open port 80:<\/p>\n\n\n\n
    sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
    sudo iptables -A INPUT -p udp --dport 80 -j ACCEPT<\/pre>\n\n\n\n
    \n
    \"Open<\/a><\/figure>\n<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    Save IPtables Rules:<\/strong><\/p>\n\n\n\n