Add the desired ports to the httpd.conf (or ports.conf file if you have one).
Code:
Listen 80
# Uncomment the following if you will be using SSL
# Listen 443
# Add any additional ports here.
# Listen ??
You can also specify a listen on only one ip/port:
Code:
Listen 192.168.1.1:8000
Next you need to set up virtual hosts on the desired ports. The easiest way to do this is to create a custom .conf file for the host with all of the settings in it and include it at the end of your apache2.conf or httpd.conf.
Code:
include /path/to/virtualhostfile.conf
Code:
<VirtualHost 192.168.1.1:8000>
DocumentRoot /path/to/html
...
</VirtualHost>
It is actually best to use names when you can; if you choose to do that you can do name based hosting. I wrote a
post on apache2 with virtual hosting if you need more resources.