Businesses and users experience havoc due to CenturyLink outage

A CenturyLink outage led to a surprising 3.5% drop in global internet traffic.

The outage was due to a technical misconfiguration issue in one of its data centers.

The error involved both firewall and BGP routing and affected not only CenturyLink’s network, but also affected other internet service providers.

Some of the companies affected by the outage were Cloudflare, Reddit, Hulu, Blizzard, Steam, Xbox Live, Discord, and Twitter.

CenturyLink alerted users to the issue on their status page, stating that the issue originated from CenturyLink’s data center in Mississauga, near Toronto, Canada.

The root cause of the incident was in incorrect Flowspec announcement.

Flowspec announcements are usually used when dealing with security incidents, such as DDoS attacks, and let companies change their entire network within seconds.

In a domino effect, CenturyLink’s incorrect Flowspec command brought down some of the routers inside its network, then, those routers began to give incorrect BGP routes to neighboring networks.

The issue was resolved when CenturyLink had other internet providers de-peer from their network.

Thankfully, the outage only took about 7 hours to fix and their network is now running correctly.

As always, if we can be of help with your network or computer, give us a call here at RHYNO Networks. (855) 749-6648