forward three ports to the the internal IP address of the BigBlueButton server. These ports are 80 (HTTP), 9123 (Desktop Sharing), and 1935 (RTMP).
sudo bbb-conf --setip external.host.org
Internally, BigBlueButton must be able to call external.host.org to make API requests. In this example, if the internal BigBlueButton server is at 192.168.10.198, add the following line to /etc/hosts (you’ll need to edit this file as root user).
sudo vi /etc/hosts