Ideally you are using domain names instead of IPv6 addresses, but to do so, you need to ensure that your application is retrieving the correct information from the Domain Name System (DNS).
In IPv4, the DNS record pointing a hostname
www to an IP address is an
A record and would look like this in a DNS zone
With IPv6, the new DNS record is the
AAAA (also known as a “quad A”) record, as in
Ultimately, we will get to a point where DNS zone files contain
A and an
AAAA record for a
host name. For example:
Today, some operational issues (see below) have prevented widespread
deployment of both
AAAA records for the same
host name, but this is the direction in which DNS
records will go.
The first question is obviously whether your application can
AAAA records. When you issue a request for
a hostname, does the underlying library even return
If your app does get an
AAAA record back, what does it do with the
AAAA record? Does
it use the record to correctly obtain the IPv6 address for the hostname?
Or does your app ignore the returned
AAAA record and only look for
It is incredibly important to realize that
can be retrieved over IPv4. In other words, just
because you can retrieve a DNS
AAAA record does not mean
you can connect to that site using IPv6.