Prerequisites.
Uncomplicated Firewall (UFW) #
The Uncomplicated Firewall, or UFW, is a simple-to-use, command-line application for working with a Linux firewall.
Install UFW.
sudo apt install ufw -y
The following UFW rules should be applied in the terminal to ensure that only ports essential to the node’s regular operation are open.
Default Settings #
sudo ufw default deny incoming
sudo ufw default allow outgoing
Allow SSH #
sudo ufw allow ssh
Allow Dojo ZMQ Ports #
sudo ufw allow 28334/tcp
sudo ufw allow 28333/tcp
Allow Bitcoin Core RPC Port #
sudo ufw allow 8332/tcp
Allow Fulcrum SSL Port #
sudo ufw allow 50002/tcp
Allow Mempool HTTP Port #
sudo ufw allow 4080/tcp
Enable UFW #
sudo ufw enable
When enabling UFW, a warning may appear informing that enabling UFW may cause connection issues with the session. Since a rule allowing SSH was already applied, confirming with “y is safe.”