From AdempiereWiki

Access via LAN not working

You have installed the database, Java, and Adempiere and at the end of it all it has been installed successfully. You have been able to run RUN_SETUP.bat/sh, RUN_SERVER2.bat/sh and even access the Adempiere system using RUN_Adempiere.bat/sh.

You then look at the following site and decided to try and access one of the services over the network using your browser.

http://en.wikiversity.org/wiki/Adempiere_Technical_Training#Installed_Services

As you hit enter after entering the address you find that you get a message that the site does not exist ("Could not connect to host"). Even when the IP address is your host system and the same as where the browser is.

A possible fix to this is to edit myEnvironment.bat/sh

You will find the file in ADEMPIERE_HOME/utils. Edit the bat for Windows or sh extension for Linux.

Find a line with ADEMPIERE_APPS_SERVER=<myServer>, where <myServer> is the name of your machine that you used when running RUN_Setup.bat/sh

Replace <myServer> with 0.0.0.0

In Windows the line should be similar to:
@SET ADEMPIERE_APPS_SERVER=0.0.0.0

In Linux it should be similar to :
ADEMPIERE_APPS_SERVER=0.0.0.0

Save the file and re-start the server (RUN_Server2.bat/sh).

I was provided with this work around and it worked for me. If you know the reason for needing to change this or how to avoid this issue, then please provide further details here.