IP Spoofing

People are operating completely sane services and anti-UDP warriors suggesting they change them because they appeared in a ddos is idiotic and harmful to the Internet. You can completely eliminate all UDP services and the untraceable DDoS problem won't go away, you've just eliminated some amplification avenues. The 1.5tbps attack didn't even use UDP so this "solution" is dead in the water and whoever is pushing it is misinformed.

Do you realize that every public DNS server in the world (root servers, recursive revolvers, Google.com NS servers, etc) can be used in an amplification attack? According to you we should name and shame every DNS developer, domain name owner, and operator.

We essentially couldn't have functioning DNS if we operated under your plan to 'fix this from both ends'. I suggest you read up on amplification attacks because I think you misunderstand how they actually work and think there is a way to 'configure' your way out of them.

This problem absolutely should not be "fixed from both ends". The right hand side (eliminate all amplifying UDP protocols) is massively disruptive (bye bye DNS) and doesn't actually fix the root issue (attackers just spoof TCP instead with a reduced amplification factor). The left hand side (BCP 38) requires fewer participants (ISPs vs server operators) and it completely solves the problem even without the slightest adoption of the stupidity on the right hand solution.

If you have ever suggested that a dns operator disable recursive resolving, you are perpetuating the problem by making people participate in an idiotic ritual that does almost nothing to improve the security of the Internet. It's the equivalent of restaurants not serving glasses of water to reduce the water shortage while farmers grow rice patties in a desert with essentially unlimited water rights.

"Yeah, this guy stole your car by asking nicely for an extra set of keys from the manufacturer. Even though the manufacturer shouldn't have allowed him to do get a key, we're holding you responsible since you technically could have kept your car in a locked garage."

Also, the gp was taking about cache poisoning, but it was only exploitable in the presence of spoofed IPs.

Blacklists are only useful to stop only a few DDoS attacks mainly amplified ones like the ones that abuse open DNS resolvers which should be cleaned up on their own, in which case you want to be blacklisting the resolvers not the machines that use IP spoofing since they do not attack you directly.

Many (heck most) DDoS attacks do not use IP spoofing, the recent and largest recorded in history just used 145,000 IP enabled cameras, and this isn't even remotely the largest botnet out there, blacklisting an entire botnet is effectively DDoSing yourself since many of those machines can be on a network with 100's or 1000's of other computers behind the same IP which many of them would be legitimate users of your service.

Notifying ISP's also doesn't help, some ISP's can do some preventative measures but what often they do is simply kill routes to your service, again it would work if you are dealing with some ISP in Slovakia if you aren't serving any customers there (granted they actually respond to you in due time) but if you are dealing with large ISP's there is little they could do and cutting them off isn't an option.

And as for as cleaning and isolating these machines this is laughable, you aren't going to be tracking down customers, even the ISP won't do that for you, and even if it did what would it do send and email that would likely be ignored? Even if you identify customer the IP belongs to it doesn't tell you anything about the device, not to mention that the customer would likely have no capability of cleaning up their machines to begin with.

IP spoofing is a problem because there are currently ways to abuse IP spoofing to amplify the attacks, if you aren't amplifying your attack using UDP protocols you will usually not going to be using IP spoofing in the first place, and automatically banning IP addresses might sound like a good tactic until you are hit with DDoS from a big botnet within your market region at which point you can't use that any more, you might ban a few IP's that seem to have access to excessive bandwidth but even that might be problematic since it can affect legitimate users.