I am assessing my company IPv6 readiness with Firefox. We have our internal DNS (dual stack) set up now responding with IPv6 address only for the host name of a test web server. I configured a test Windows machine (dual stack), with said DNS, and was able to ping with the test web server with host name.

Now comes Firefox. I can access my test web server with IPv6 URL (http://[a:b:c:d:e:f:g:h] kind) but when I cut and paste the host name (the one I successfully pinged with) , no, Firefox can't access it. What could be the problem that cause Firefox to not resolve that name to the proper address? Ping works fine, why doesn't Firefox?