I am going to start over with my questions, as I think I may now have a handle on what you are asking.
- It seems to me that you are saying that your web server responds using Firefox to any IPv4 or IPv6 address which is valid for the machine.
- It also seems that you are saying that LWP is able to handle contacting the web server using any IPv4 address for the machine.
- It seems like you are stating that using LWP to access an IPv6 address for the server is failing, even if it is an identical URL that Firefox can use to access the server.
Do I have that correct?