Tag: ufw

  • ufw

    The Uncomplicated Firewall (ufw) is a user-friendly interface for managing netfilter, the standard firewall utility included with most Ubuntu and Debian-based Linux distributions. ufw simplifies firewall configuration by providing straightforward commands for enabling, disabling, and managing firewall rules without requiring extensive networking knowledge.

    To enable ufw to start automatically at boot:

    systemctl enable ufw

    To start or stop the firewall:

    ufw enable
ufw disable

    To see the status, run

    ufw status
ufw status numbered

    Open Ports

    Here are some commands to open ports.

    ufw allow ssh
ufw allow http
ufw allow https
ufw allow 3333/tcp

    Following command open tcp ports 8000 to 9000.

    ufw allow 8000:9000/tcp

    Disable all other ports by default for incoming and allow all outbound traffic

    ufw default deny incoming
ufw default allow outgoing

    Block a port, below example will block port 80

    ufw deny 80/tcp

    Whitelist an IP

    To allow an IP to access all services

    ufw allow from IP_ADDR_HERE

    To allow to specific PORT

    ufw allow from IP_ADDR_HERE proto tcp to any port PORT_HERE
ufw allow from IP_ADDR_HERE proto udp to any port PORT_HERE

    Enable Logging

    To enable logging, run

    ufw logging on

    By default ufw logs to /var/log/kern.log.

    To log to different file, edit

    vi /etc/rsyslog.d/20-ufw.conf

    Uncomment the line

    :msg,contains,"[UFW " /var/log/ufw.log

    rstart rsyslog

    systemctl restart rsyslog

    To allow all Cloudflare IP addresses for web traffic, use the following command. This is useful if your server is behind Cloudflare’s CDN:

    for cfip in `curl -sw '\n' https://www.cloudflare.com/ips-v{4,6}`; do ufw allow proto tcp from $cfip comment 'Cloudflare IP'; done

    To list available apps, run

    ufw app list

    See firewall