Optus says a “routine software upgrade” was the cause of last week’s catastrophic nationwide outage.
“We have been working to understand what caused the outage on Wednesday, and we now know what the cause was and have taken steps to ensure it will not happen again,” the Optus statement said.
“At around 4.05am Wednesday morning, the Optus network received changes to routing information from an international peering network following a routine software upgrade.
“These routing information changes propagated through multiple layers in our network and exceeded preset safety levels on key routers which could not handle these.
“This resulted in those routers disconnecting from the Optus IP Core network to protect themselves.”
The repair job took Optus “longer than we would have liked” and “required a large-scale effort” which included physically reconnecting routers across various sites.
Those who are still customers have been reassured that Optus “made changes to the network to address this issue so that it cannot occur again.”
Time will tell.