> AS396531 - Allegheny Technologies Incorporated

That appears to be a steel/alloys company. Why are they operating BGP equipment?

Any company which operates large factories probably has its own ASN and runs its own networks. Every thing's gotta be internet-enabled these days, and at a certain scale, it becomes cost-effective.

Why not? Pretty much everyone that needs a redundant internet connection (dual ISP) does it.

> Why not?

It seems silly to me that an end user company not providing any network services which only has a 256 IP block has the ability to break a significant portion of the internet with a configuration mistake. There are several ways to setup dual ISPs and routing that don't involve such risk.

You need BGP and provider independent space for your two ISPs to both announce your space. What's the alternative approach?

Don't rely on a single IP routing through multiple ISPs, use DNS.

what? this statement makes no sense from a networking perspective.

thisissue still exists if you break up your IP space, it just makes it far harder to manage.

Most places that are just doing it for that reason won't be advertising anything other than their own /24 or whatever though. You have to fuck up pretty spectacularly (and have your upstream providers do the same) to be able to accomplish what has happened here.

Pittsburgh is a town that (used to be) run by steel. Even a few decades after that dominance, this particular company is still a $4B one on the S&P 400. I'm pretty sure this is the company that my grandfather worked at for decades; his brother did from high school to retirement (except during World War II). They apparently significantly polluted the air in the high school district next to mine ten years ago.

It doesn't surprise me at all that they are still a part of infrastructure, somehow.

They aren't the original leaker.

Update: sorry, I may have been wrong. Hard to see clearly in the fog of BGP.

Can you elaborate?

Seconded. I've received notices from multiple carriers that ASN 396531 is the root cause of the leak.