Optus network outage evokes memories of infamous 2021 Facebook crash

Optus logo displayed on a store front in Sydney
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A network outage at Australian telecoms giant Optus left millions of Australians without internet access. 

Optus, the second largest telecoms provider in the country, said more than 10 million people had been affected by the disruption, including businesses. 

Payment systems used by thousands of businesses were taken offline during the incident, with Australians also experiencing transport delays and finding themselves unable to access vital services. 

Scores of people were also unable to contact the emergency services. 

The Optus network outage appears to have had a cascading effect across other Australian carriers, with Aussie Broadband and Moose Mobile customers unable to access services. 

The exact cause of the disruption is yet to be determined. However, Optus CEO Kelly Bayer Rosmarin attributed the outage to a “technical fault”. 

The firm said there is no evidence at this time that the outage was caused by a cyber attack and it will continue to investigate the incident. 

“What I can say is that it was a technical network issue, and that our teams have worked very, very hard to get services restored as quickly as they possibly could,” Rosmarin told the Australian Broadcasting Corporation (ABC).  

Optus network outage: Possible causes

The nationwide outage bears some similarities to a previous incident in which Facebook services were taken offline, according to experts.

Speaking to the Guardian Australia, Matt Tett, managing director of network analysis company Enex TestLab, suggested the issue could be due to issues with Border Gateway Protocol (BGP). 

BGP is designed to exchange routing between internet systems and determines the best network routes for data transmission across the internet. 

At the time of the outage, Cloudflare recorded a spike in BGP announcements, suggesting this could be the cause of the incident. 


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“Mobile & NBN #Internet services are unavailable for millions of Optus customers across Australia,” Cloudflare said in an advisory. “Cloudflare Radar data shows traffic dropping around 16:45 UTC, reaching a state of near-complete outage within a half hour. 

Facebook and its sister platform Instagram were knocked offline for more than five hours in 2021 due to a BGP-related incident.  

The company attributed the outage to a configuration change in routers that were used to direct network traffic between data centers.

Ross Kelly
News and Analysis Editor

Ross Kelly is ITPro's News & Analysis Editor, responsible for leading the brand's news output and in-depth reporting on the latest stories from across the business technology landscape. Ross was previously a Staff Writer, during which time he developed a keen interest in cyber security, business leadership, and emerging technologies.

He graduated from Edinburgh Napier University in 2016 with a BA (Hons) in Journalism, and joined ITPro in 2022 after four years working in technology conference research.

For news pitches, you can contact Ross at ross.kelly@futurenet.com, or on Twitter and LinkedIn.