Telstra have announced that their internet service domain servers are under attack.
As a result, many thousands of customers are unable to use their home internet, including NBN.
🔒 Update: We've identified the issue and are working on it. Some of our Domain Name Servers (DNS) used to route your traffic online are experiencing a cyber attack, known as a Denial of Service (DoS). Your info isn't at risk. We're doing all we can to get you back online.
— Telstra (@Telstra) August 2, 2020
A solution is being worked on but it’s not clear when a fix will be available.