In order to test if firewall security settings are blocking SELweb, please navigate to selweb.com/test. If the picture loads and audio plays, then SELweb will function properly. If the picture does not load and audio does not play, IT should whitelist the following domains:
.selweb.com
.cloudfront.net
The following domains are also referenced from selweb.com and can be whitelisted, but the site will operate without them:
fonts.googleapis.com
fonts.gstatic.com
www.google-analytics.com