If you are having trouble opening a jnlp file (e.g., for IPMI console access) you can try some of these steps.
Tell Firefox to allow pop-up windows for this site
Tell Firefox how to handle the filetype .jnlp
Tell it to open it with /usr/bin/javaws
Tell Java to allow the site to run applications
If you get “Application Blocked by Java Security” you can fix that by editing an exceptions list.
Modify file ~/.java/deployment/security/exception.sites
Each line in this file should be a protocol and domain name or IP address for the exception, e.g.:
http://172.20.0.19 http://172.20.0.20