WhatismyIP displays what I now realise is an IPV6 address. However, my ISP expects me to provide an ISP4 address when making tech queries.
Also, I note that if an email I send is rejected, the rejection message shows the sender (me) as having an IPV4 address.
Is there any way in which, knowing an IPV6 address, one can look up the corresponding IPV4 address? Clearly the email blocker I mention above 'sees' my email as coming from an IPV4 address, even though WhatsmyIP 'sees' me as having an IPV6 address.
I hope this makes sense.
Your question definitely makes sense. 🙂
Unfortunately, not all IPv6 addresses can be converted to an IPv4 address. In my experience, if an IPv6 address starts with 0000:0000 then your IPv6 address can most likely be converted to IPv4. We're working on a calculator now that will perform this function if possible.
When you send email, essentially you're sending it through an email server owned by your ISP or possibly Google (@gmail.com), etc. Their email server could be connected via IPv4 so the rejection email you're getting is most likely showing the IPv4 of the email server and not your computer.
If your ISP is assigning IPv6 but asking for IPv4 when making tech queries, that's a lack of something on their side or their support ticket software. This is not uncommon at this point with IPv6 still being the new kid on the block. It's in use but not supported in all software including some firewalls, etc.