Internet Protocol version 6 (IPv6):
Testing both for IPv4 and IPv6, IPv6 preference is reproducable: http://www.ipv6proxy.net
This tool is like a IPv6 process. This open proxy is a forwarding proxy server that is accessible by any internet user, and is also useful for its fast propagation around the world after a changed DNS.
Analyze failures using ipv6proxy.net:
- The requested site (example.com) does not appear to have an IPv6 address.
- The requested resource could not be loaded. libcurl returned the error:
Unknown SSL protocol error in connection to example.com:443
– The reverse server name, IPv6 address and certificate combination may not match;
– Reported issue 2018-09-07: probably in case of a web server without TLSv1.0.
Eg IPv6 setup for a VPS:
Common mistakes with IPv6:
- AAAA is always preferred over A. The application server can be limited to IPv4;
- Value, eg using ODBC, between brackets such as [2a01:7c8:aab1:282::1].
Linux statement to find out the IPv6 address see: find-ipv6-address.txt
eg 2a01:7c8:aab1:282::1 in this output:
or send a mail to …@gmail.com and find the IPv6 address in source code in your webmail application.
A firewall may block:
Open a not standard SSH port for IPv6 too.
An IPv6 address is changing all the time:
Stabilize login checking for security.