Ubuntu UFW 3x specific IP addresses only to access a specific port

First lets deny all access:

sudo ufw default deny incoming
sudo ufw default allow outgoing

Now limit out inbound traffic to ip via these ports:

sudo ufw allow from 1111.1111.1111.1111 to any port 33
sudo ufw allow from 2222.2222.2222.2222 to any port 33
sudo ufw allow from 3333.3333.3333.3333 to any port 33

If adding a specific protocol to the rules above:

sudo ufw allow from 1111.1111.1111.1111 proto udp to any port 33

Now check your rules:

sudo ufw status

To delete these rules at any time:

sudo ufw delete allow from 1111.1111.1111.1111 to any port 33

Source:

https://help.ubuntu.com/community/UFW

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-14-04