As far as we know, the Optus outage was caused by a configuration change to the Border Gateway Protocol (BGP) routes that allow networks to communicate.
Here’s a quick breakdown of the issue, what BGP does, and how it can be prevented.
The facts:
- Optus had a 14-hour long outage to most of their network on the 8th of November, 2023
- Many businesses were unable to operate
- Small businesses were unable to take payment
- Some customers were reported being unable to make emergency calls to triple-0
- Customers were left in the dark during the outage
Why did it happen?
- Optus claims a BGP change brought down the network
- The BGP change was a scheduled change on the network that went wrong
- The change appears to have been on Singtel equipment, Optus’ parent company
- The change led to bad routes propagating to the Optus network in Australia
What is BGP (in a nutshell)?
- Border Gateway Protocol or BGP is the protocol used by the majority of networks around the world make the Internet (a network of networks) available to users, services, etc.
- BGP is a protocol used by networks to help traffic identify the best path to its final destination
- BGP is the means of negotiation between networks to help networks connect to other networks
How did it go wrong?
- BGP learns it’s routes (or paths) by negotiating with other trusted devices and therefore sharing routes
- Imagine you’re driving from Sydney to Melbourne. Think of the issue that occurred as a ‘traffic director’ who gave you the wrong direction on how to get from Sydney to Melbourne
- When the routes go the wrong way, they are typically ‘junked’ by their next hop if the path is not configured
What should businesses do to protect themselves in thefuture?
- Use more than one Internet link for essential services
- Your secondary Internet link should be served by a different provider, and if possible via a different connectivity, ie, 5G, NBN, private links
- Consider the use of bonded internet services to have seamless cutovers between services
- Small businesses should consider having a backup Internet link on their EFTPOS and payment services
