how do I access a virtual site on a local lan?

This sounds to me like there was likely an Apache configuration file that was set up to point all bare IP requests to the /var/www directory. By appending the directory name of the site that you were seeking, you could load the page normally. In order to do something similar, you'll need a "bare" Apache config file to exist.

Here's how you make one:

0. Open Terminal (if it's not already open)
1. Navigate to the Apache sites-available directory:

   cd /etc/apache2/sites-available
   

2. Create a new file that will be used internally. Perhaps you can call it something like 000-local.conf:

   sudo vi 000-local.conf
   

   _{Note: Feel free to use any text editor that you are comfortable with. The example of vi above is more a force of habit than a direct endorsement.}
3. Paste the following into your new file:

   <VirtualHost *:80>
           ServerAdmin [email protected]
           DocumentRoot /var/www
   
           ServerName 192.168.1.2
           ServerAlias 192.168.1.2 192.168.1.*
           DirectoryIndex index.php index.html
   
           ErrorLog ${APACHE_LOG_DIR}/local-error.log
           CustomLog ${APACHE_LOG_DIR}/local-access.log combined
   </VirtualHost>
   
   <Directory /var/www>
           Options FollowSymLinks
           AllowOverride All
   
           Order Allow,Deny
           Allow From All
   </Directory>
   

4. Save the file
5. Enable the config file:

   sudo a2ensite 000-local.conf
   

6. Restart (or reload) Apache:

   sudo service apache2 restart
   

7. Give it a go in your browser of choice

Some things to note:

• if any other configuration file has 192.168.1.2 as its ServerName, then there will be a conflict. You will want to ensure that every other site has a FQDN (Fully Qualified Domain Name — Something like website.com) as its ServerName value.
• if a configuration file is configured to listen for * in the ServerAlias, then you'll want to ensure it appears after 000-local.conf alphabetically in the directory.

So long as the sites contained in the directory will not force a redirection from 192.168.1.2/website.com to website.com, then you should be able to access these resources locally without first performing a DNS lookup outside the network.