FOP2 Community Forum

You might have the Elastix firewall enabled, without a rule to allow connections to port tcp/4445. For a quick test, if you have that firewall enabled, DISABLE it and try again. (Your 2nd command with the Can't listen error is logical, you cannot start fop2 twice, it was already running).

How did you install? If you use Elastix or FreePBX rpm, the scripts are located in /etc/asterisk/fop2, and any invokation of fop2_server must included the -c command like parameter, like /usr/local/fop2/fop2_server -c /etc/asterisk/fop2 --test /usr/local/fop2/fop2_server -c /etc/asterisk/fop2 --register etc