The changing ports are not a problem - some ports are dynamically assigned. See this for a list of key ports: http://www.jboss.org/community/wiki/UsingJBossBehindAFirewall The telnet syntax is "telnet [hostname] [port]", not [username]. The [hostname]s I suggested were based on the netstat output. If telnet cannot access port 1099, then Eclipse will not be able to access it either, and thus will never be able to tell whether the app server is running. All I can think of at this point is that a firewall is blocking the ports. Depending on how insistent your firewall is in doing this blocking, you might have to uninstall the firewall software to get this working. I have had to uninstall ZoneAlarm and Symantec on occasion to get some software to work, usually because I left those firewalls on 'automatic' mode and they guessed wrong. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4253102#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...