$ sudo ufw allow from 104.22.11.213 to 222.222.222.222 port 25 proto tcp Allow connection on specific interface

$ sudo ufw allow from 104.22.11.213 to any port 25 proto tcp Let us allow connections from an IP address called 104.22.11.213 to our port 25, enter: In this example, you want to allow ALL connections from an IP address called 104.22.10.214, enter: We can allow port ranges too say, tcp and udp 3000 to 4000: $ sudo ufw allow 1194/udp comment 'OpenVPN server' Allow port ranges via ufw $ sudo ufw allow 443/tcp comment 'accept HTTPS connections'

$ sudo ufw allow 80/tcp comment 'accept Apache' The syntax is as follows to open TCP port 80 and 443: Say you want to open ports and allow IP address with ufw. Sample outputs: Firewall stopped and disabled on system startup Step 4 – Open specific incoming connections/ports If you need to stop the firewall and disable on system startup, eenter:

Want to disable the UFW based firewall? Try We can verify that easily as follows using the systemctl command: Remember, once UFW enabled, it runs across system reboots too. In other words, the firewall will drop all incoming traffic except for ssh TCP port 22. See “ How to limit SSH (TCP port 22) connections with ufw on Ubuntu Linux” for more information. $ lastlog -u Īnd here is what I see: Username Port From Latest $ sudo ufw allow proto tcp from 202.54.2.5 to 172.24.13.45 port 22īut how do I find out my static IP 202.54.2.5 on Ubuntu server itself? Try the w command or lastlog command: In that case, only allow ssh access from the static IP address such as 202.54.2.5 to Ubuntu server IP address 172.24.13.45: Some sysadmins have a static IP address (such as 202.54.2.5) at home or office location. If you are running ssh on TCP port 2222 or TCP port 2323, enter: We can easily open SSH TCP port 22 using UFW as follows: The next logical step is to allow incoming SSH ports. $ cat /etc/default/ufw Step 2 – Open SSH TCP port 22 connections Make sure the directive IPV6=yes do exists in /etc/default/ufw file. $ sudo ufw default deny incoming Enabling IPv6 support Let us block all incoming connection and only allow outgoing connections from the Ubuntu 20.04 LTS box: It is always a good policy to closes all ports on the server and open only required ports one by one. The default policy firewall works out great for both the servers and desktop.

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