This works for JBOSS 4.0.5.GA! hopefully, it will work on some other versions. The important thing is to change the port number for the services you are running in your application – http, rmi, jndi, Webservice e.t.c. You will find these in the following xml files -All xml are in the server directory JBOSS.
Leave the first instance of your JBoss unchanged. In the 2nd instance, for example, update the xml files as described below:
…<jboss folder>…/server/default/deploy/jbossweb-tomcat55.sar/server.xml:
update 8080 to 18080
…<jboss folder>…/server/default/conf/jboss-service.xml:
update 1099 to 11099
update 1098 to 11098
update 4445 to 14445
update 4444 to 14444
…<jboss folder>…/server/default/conf/jboss-minimal.xml:
update 1099 to 11099
update 1098 to 11098
…<jboss folder>…/server/default/deploy/jms/uil2-service.xml – update 8093 to 18093
…<jboss folder>…/server/default/conf/jboss-service.xml – update 8083 to 18083
