Internet service provider Internode has moved to a production IPv6 environment for all subscribers, two years after trials began on the protocol.
IPv6 would remain opt-in for the near future but Internode now allowed all customers to access the protocol natively by changing the ADSL connection address on their router.
Internode subscribers on the National Broadband Network would also be able to use the protocol.
Simple use of IPv6 provided no tangible differences to most end-users but the service provider indicated it would look to offer customer-facing DNS management in future.
Internode had campaigned for rapid adoption of the protocol for some time, upgrading its own backbone network to support IPv6 in 2008 before offering a limited trial to users in November 2009.
It had tested the protocol with approximately 200 users at any one time until this week.
Managing director Simon Hackett said the protocol change was an "under the hood" alteration.
"Done right, most customers won't notice the change to IPv6," he said.
The regional internet address registry APNIC distributed the last remaining IPv4 address blocks in February this year, prompting further urgency for adoption of the IPv6 protocol.
Service providers in Australia had been comparatively slow in adopting the protocol in production environments.
Some telcos stockpiled enough IPv4 addresses to delay an immediate transition.
Telstra said in June it had begun deploying a dual-stack environment with simultaneous compatibility for IPv4 and IPv6, though it was unclear when this environment would be moved into production.
Telstra and the Australian Department of Defence had each acquired a /20 of IPv6 address, or a block large enough to fit 2^108 addresses.
A Defence spokesman would not clarify how the addresses were to be used.
TPG had also begun quietly testing its own IPv6 environment earlier in the year and it was believed a deployment had begun on peering links operated by backhaul subsidiary PIPE Networks.
iiNet chief executive Michael Malone has continually argued there was no business case for short term adoption of IPv6.
A worldwide day commemorating the protocol's adoption saw major companies including Google and Facebook offer IPv6-only versions of their websites. The internet giants were joined by the Queensland University of Technology, as well as the Australian chapter of the Internet Society.
However, quick reversions back to a dual-stack of IPv4-only versions of the websites led some to doubt the long-term repercussions of global IPv6 efforts.