ufw - ServerOK

ufw is firewall in Ubuntu.

To enable

systemctl enable ufw

To list available apps, run

ufw app list

To see the status, run

ufw status

To see firewall rules in a numbered format

ufw status numbered

Stop ufw

ufw disable

Start ufw

ufw enable

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

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

To enable logging, run

ufw logging on

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

To log to differnt file, edit

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

Uncomment the line

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

rstart rsyslog

systemctl restart rsyslog

Allow cloudflare IP in ufw

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