An interesting sub-thread to this could be:

Have you ever unintentionally crashed a device by running a perfectly innocuous command?

1. Crashed a 6500/Sup2 by typing "show ip dhcp binding".

2. "clear interface XXX" on a Nexus 7K triggered a cascading/undocument Sev1 bug that caused two linecards to crash and reload, and take down about two dozen buildings on campus at the .edu where I used to work.

3. For those that ever had the misfortune of using early versions of the "bcc" command shell* on Bay Networks routers, which was intended to make the CLI make look and feel more like a Cisco router, you have my condolences.  One would reasonably expect "delete ?" to respond with a list of valid arguments for that command.  Instead, it deleted, well... everything, and prompted an on-site restore/reboot.

BCC originally stood for "Bay Command Console", but we joked that it really stood for "Blatant Cisco Clone".

On Tue, Feb 16, 2021 at 2:37 PM John Kristoff <jtk@dataplane.org> wrote:

Friends,

I'd like to start a thread about the most famous and widespread Internet
operational issues, outages or implementation incompatibilities you
have seen.

Which examples would make up your top three?

To get things started, I'd suggest the AS 7007 event is perhaps  the
most notorious and likely to top many lists including mine.  So if
that is one for you I'm asking for just two more.

I'm particularly interested in this as the first step in developing a
future NANOG session.  I'd be particularly interested in any issues
that also identify key individuals that might still be around and
interested in participating in a retrospective.  I already have someone
that is willing to talk about AS 7007, which shouldn't be hard to guess
who.

Thanks in advance for your suggestions,

John