Issue: Users or services cannot connect to your server, application, or device from an external network (e.g., the internet or another subnet). Connection attempts time out or are actively rejected.
sudo iptables -L -n -v Look for a default policy of DROP or REJECT on the INPUT chain. Example blocking line: inbound traffic blocked, check firewall settings
The firewall is blocking the incoming (inbound) traffic. Issue: Users or services cannot connect to your
sudo ufw status verbose If inactive, enable it with sudo ufw enable . If active, check for rules like Deny from any or missing Allow rules for your port. inbound traffic blocked, check firewall settings
sudo pfctl -s rules Disable temporarily: