No, it's not just you.

Large swaths of the United States experienced internet connection problems today, with several major ISPs apparently affected. Comcast, Verizon, and AT&T all appeared to have issues, with Comcast blaming the outage on an "external network issue."

This outage falls just after the one-year anniversary of a major DDOS attack on Dyn that crippled the internet for a day in October of 2016.

Tweet may have been deleted

According to DownDetector, which tracks internet outages, Comcast customers experienced connectivity issues in "Mountain View, Denver, Portland, Chicago, Seattle, New York, San Francisco, Houston, Minneapolis, and Boston."

There are no firm reports yet as to the cause, although some speculated that it might be some sort of attack.

Tweet may have been deleted

Meanwhile, Level 3 — a major ISP — told Mashablethat a "configuration error" caused a 90 minute service disruption.

"On Monday, Nov. 6, our network experienced a service disruption affecting some customers with IP-based services," wrote the spokesperson via email. "The disruption was caused by a configuration error. We know how important these services are to our customers. Our technicians were able to restore service within approximately 90 minutes."

A Verizon spokesperson explained to Mashableover email that "[no] Verizon widescale Internet outages now that I'm aware of."

We've reached out to Comcast and AT&T, and will update this story when and if we hear back.

UPDATE: Nov. 6, 2017, 1:16 p.m. PST Comcast now claims that the problem has been "resolved for almost all customers."

Tweet may have been deleted

This story has been updated to include statements from Level 3 and Verizon.