The world will run out of internet addresses "within weeks", according to one of the founding fathers of the web, a report said on Friday.
Vint Cerf, who helped create the web by connecting computers using Internet Protocol (IP) addresses, said it was his "fault" that the 4.3 billion addresses created were running out, the Sydney Morning Herald reported.
"I thought it was an experiment and I thought that 4.3 billion would be enough to do an experiment," Cerf, who is Google's vice president and "chief internet evangelist", was quoted as saying in an interview.
"Who the hell knew how much address space we needed?"
In 1977, Cerf created the web protocol IPv4, which connects computers globally, as part of an experiment while working with the US Department of Defense.
He said he never expected his experiment "wouldn't end".
"It doesn't mean the network stops, it just means you can't build it very well," Cerf said.
IP addresses are the unique sequence of numbers assigned to each computer, website or other internet-connected devices. They are not the same as website domain names.
The overwhelming number of devices now accessing the internet means the addresses are running out fast.
To resolve the crisis, an updated protocol for the internet, IPv6, currently being planned by the industry, will create trillions of addresses.
As Google vice president Cerf, who was in Australia to address a conference, said he thought the new chief executive of the California-based giant, Larry Page, was ready to lead the company into the future.
In a surprise move, Google announced on Thursday that co-founder Page would replace Eric Schmidt as chief executive in April.
Schmidt, 55, a former chief executive of Novell, will remain with Google as executive chairman, focusing on deals, partnerships, customers and government outreach, Google said.
He will also act as an adviser to Page, 37, who served as CEO previously, from 1998 to 2001.
Cerf said Schmidt had been chief executive for 10 years -- "a nice round number" -- and Page was ready to lead the company into the future.
"Larry and Sergey are 10 years older than they were when they thoughtfully hired Eric to be the CEO... so everybody's growing up," Cerf said.
Google has grown over the past decade from a start-up battling other Internet search engines into a technology giant with nearly 25,000 employees and annual revenue of nearly $30 billion.
The company meanwhile reported its fourth-quarter net profit increased to $2.54 billion from $1.97 billion a year ago, while revenue rose 26% to $8.44 billion.