If a bot is using its actual source address, you can block its IP at the edge (and even ask the ISP to investigate). Thanks to IP spoofing, that's totally ineffective, so instead the only way to make the attack stop is to null route the host.
> "many were garbage Web attack methods that require a legitimate connection between the attacking host and the target, including SYN, GET and POST floods."
I constantly see references relating to DDoS attacks about how IP spoofing is such an obvious trick to use but I've never seen any way to actually do it. Why wouldn't every device on the internet spoof their IP?
[1] https://web.archive.org/web/20160922021000/http://krebsonsec...
https://spoofer.caida.org/summary.php - compromise a device in one of the ASes not marked "unspoofable." Those ASes do not consistently perform packet ingress filtering.
That's not to say that DDOS attacks stop being possible, but at least they become traceable.
Most countries don't allow cars on the road that are unsafe due to lack of maintenance. Perhaps it's time to do something similar for internet-enabled devices that cause serious harm to others. Hold the user, manufacturer, or network operator responsible for harm caused by their lack of maintenance.