how to config apache2 at local network

Set up your local DNS server with the domains you want to use on your network, and then set up Apache virtual hosts to process those domain names as the requests from the web browsers arrive at your web server.

Getting from www.example.com to example.com via mod_rewrite and URL rewriting (and a 301 or 302 redirect), or via Server Admin and its capability to permit you to have web site aliases. It's also possible to set this up via CNAME (alias) entries in your local DNS server definitions, as described in one of the articles listed above.

I'd suggest using registered domains, as that avoids problems if/when you start operating with the rest of the Internet, and particularly when you're accepting in-bound requests for your web server from the Internet.

I'd also suggest configuring your network out of the 192.168.0.0/24 and 192.168.1.0/24 subnets now, as (when you get around to needing them) VPN connections need IP routing and IP routing doesn't work well when you have the same IP subnet on both ends of the VPN connection. It's usually easier to change this earlier rather than later. Look to change this to some other private subnet within the 192.168.0.0/16 block, or into subnet in the 172.16.0.0/12 or 10.0.0.0/8 blocks.

Edit your hosts file with "sudo vi /etc/hosts" or "sudo nano /etc/hosts" and add the following lines:

192.168.0.1 hostone.com

192.168.0.1 hosttwo.com

192.168.0.1 hostthree.com

If you have configured Apache's virtual hosts correctly, it should sort it out.