The ability to check ports is a most network tool. I cannot seem to check IPv6 ports, only IPv4.

Its great that you have this tool as a trusted and known provider. BTW same goes the the email checking. Never trusted any other website that claims to verify email as I expect they are just collecting emails for spam!

Any chance of adding IPv6?

IPv6 port check is supported by the same tool. Instead of an IPv4 address, you can type in an IPv6 address in the 'Hostname or IP Address' field. Cheers!

After additional attempts I figured out what is happening and why it was failing for me.

I am using Chrome on Windows and I am cutting and pasting the IPv6 address from the "Manage Dynamic DNS Services" pages.

If I use the Manage Dynamic DNS Service and select the address by highlighting with the mouse from right to left (Host LSB to Prefix MSB) or left to right, or double clicking on the address to highlight the address it works every time.

If I use the Manage Alias or Manage DNS Records and copy the address by selecting with the mouse from right to left, without being too careful about where I stop, which highlights the address but has a "TAB" before the prefix and hence is invalid when I paste it into the IP address box or the Test Port tool.

I can see this by pasting the addresses into a text document.
Select address by: -

Double clicking with mouse to highlight address and copy --------------------------- no tab prefixed
Selecting address with mouse from left to right ------------------------------------ no tab prefixed
Selecting with mouse from right to left and stopping exactly at the MSB ---------- - no tab prefixed
Selecting with mouse from right to left and overshooting the MSB of the prefix, which does not highlight any additional text on the page but adds a leading TAB to the address. Which you can see when pasting the address into a text document.

Now I know I will be more accurate when cutting and pasting from the pages with tables. Although for those (like me :-)) that are used to selecting this way, a quick input check to remove any leading TAB would a nice tweak.

Thanks for the great tools on your site and the quick responses on the forum. This kind of service is why I will continue to renew and what was severely lacking with the previous company and hence why I left. That and they were twice the price for that crappy support!

LSB Least significant Byte
MSB Most significant Byte