Re:A detailed look at the router provided by my ISP
by ficklepickle on Thursday March 26, 2020 @07:28PM
(#22699068)
That is a really good point and one I hadn't considered.
Is it really that easy for a single device to take down a neighborhood? For example, could a bad actor trivially disrupt a node with a modified modem? I guess that would be difficult to defend against.
I don't know enough about docsis to say if it has any protections against out-of-spec devices.
I don't know why I'm surprised when things outside my area of expertise are fragile, considering things inside my area of expertise are fragile.
Re:A detailed look at the router provided by my ISP
by lima on Friday March 27, 2020 @09:03AM
(#22702510)
> Is it really that easy for a single device to take down a neighborhood? For example, could a bad actor trivially disrupt a node with a modified modem? I guess that would be difficult to defend against.
Yes, similarly to how you could jam a radio frequency. Fortunately, this is rare and only ever happens due to hardware failures in modems.
No, the shared medium in this case is referring the last part of the cable network where everyone in a neighborhood is transmitting effectively onto the same cable.
All it takes is a single device with a broken configuration to spew crap onto the wrong channels, taking down the whole neighborhood. https://en.wikipedia.org/wiki/DOCSIS#Physical_layer
On the Internet it stops being a shared medium the minute it gets out of the cable network into fiber/ethernet switched+routed interconnections.