[wild_preference]

Booters are cheaper than $thousands. And while it may cost someone $thousands to keep you offline for days, it probably doesn't. And even if it did, you probably want a better response than "guess we're offline now, lol, l8r" when someone chooses to spend $dozens shutting you down for a couple hours.

If DDoS protection isn't the point, what is?

I don't think it's discussed enough in our circles the various aspects of the internet that are more or less broken. Like how easy it is for anyone to take you offline. How easy it is to spoof IP addresses. How useless IP address blocking is. How we demand infinite bandwidth for a low, fixed, monthly price yet don't want to be on the hook when our toaster is DoSing our neighbor and causing real financial damage.

But at the same time we share these little haproxy/fail2ban tips that don't work under actual threat, and then we lament that people use services like CloudFlare instead of talking seriously about how we depend on the free services of large companies, whether it's CloudFlare's DDoS protection or Google's reCaptcha, to prevent real abuse.

[blackflame7000]

Is Cloudflare effectively a super large HAProxy instance? I've always wondered how they are able to absorb so much traffic.

[wtarreau]

I don't think they use haproxy (or at least they don't heavily rely on it). But once you start with properly scalable tools, you "just" need to have a high bandwidth and many machines, and everything becomes easy. Think about it for a second, put a 40 GbE NIC into an single-socket haproxy 1U pizza box, you get this for $800. Take 25 of these in a rack, connect this to an L3 switch doing ECMP and you have 1 Tbps of DDoS absorption capacity. For $16K. I know pretty well I'm oversimplifying the problem, but it always starts this way, and after this you adjust for various aspects (small packets, reflection using tools like PacketShield, TLS handshakes using more CPU cores, large connection counts using more RAM) and that's about all.

The heaviest and hardest to maintain features in these environments are the fat stuff that customers want (WAF, monitoring, UI, config versioning, etc). But basic protection is trivial if you can afford the bandwidth.

[blackflame7000]

Wow very interesting! Obviously, you simplified a good deal but it's "relatively" much simpler than what I had envisioned.