with ufw enabled (Debian based distros), you can use `ufw` command to allow traffic to specific ports. Use below command to allow access to port 9000 ```sh ufw allow 9000 ``` Below command enables all incoming traffic to ports ranging from 9000 to 9010. ```sh ufw allow 9000:9010/tcp ``` ### firewall-cmd For hosts with firewall-cmd enabled (CentOS), you can use `firewall-cmd` command to allow traffic to specific ports. Use below commands to allow access to port 9000 ```sh firewall-cmd --get-active-zones...