Akamai, whose operation helps data move around the internet, said on its website earlier Thursday that it was investigating “an emerging issue with the Edge DNS service.”
By about 12:50 p.m. ET, Akamai said it fixed the issue and the service seemed to be back to normal.
Oracle had also pointed to Akamai as the source of the issue, which impacted some Oracle cloud properties, but it said resources within its own cloud service were not affected.
Delta Air Lines, British Airways, Capital One, Go Daddy, Vanguard, UPS, LastPass, AT&T and Costco were among the websites loading slowly or showing “DNS failure” Thursday afternoon.
The Domain Name System is like a phone book for websites. The technology figures out the right IP addresses to use when people try to go to individual websites. The Edge DNS service from Akamai takes care of this work for apps and websites and protects against distributed denial-of service, or DDoS, attacks.
The outage caused some real-world disruptions. For example, Delta customers could not use the airline’s website or app to check into flights until Akamai fixed the problem.
-CNBC’s Leslie Josephs and Jordan Novet contributed to this report.