[Koha] need help with accessing koha from outside via DynDNS

[Mark Alexander]

Excerpts from Heinz-Jürgen Oertel's message of 2020-02-06 13:32:34 +0100:
> I can reach my network vi   something.dnshome.de 
> With a port forwarding 80 -> 80 in the network router I can reach the test 
> page of the apache server.
> How  can I reach the koha server

It's possible that Koha is listening on a port other than 80.  This is
controlled by the VirtualHost line(s) in your Koha installation's
configuration file in /etc/apache2/sites-available/INSTANCE.conf, where INSTANCE
is the name of your Koha instance.

You can see what ports are in use with this command:

netstat -pn --tcp --listen | grep apache