"Antiyanks" is back at it again and has switched tactics to spamming a massive number of comments in a short period of time. In addition to being annoying (and sad and pathetic), it's having a deleterious effect on performance and drowns out any discussions happening in those posts. That spam also federates as well as the eventual removals, so it's not limited to just the posts being targeted.
Looking at the site config for the home instance of the latest ~~two~~ three alts, the rate limits were all 99999999. 🤦♂️
Rate limits are a bit confusing, but they mean: X number of requests per Y seconds per IP address.
The comment API endpoint has its own, dedicated bucket. I don't recall the defaults, but they're probably higher than you need unless you're catering to VPN users who would share an IP.
Assuming your server config is correctly passing the client IP via the XFF header, 20 calls to the /create_comment endpoint per minute (60 seconds) per client IP should be sufficient for most cases, though feel free to adjust to your specific requirements.
Edit: A couple of instances accidentally set the "Messages" bucket too low. That bucket is a bit of a catch-all for API endpoints that don't fit a more specific bucket. You'll want to leave that one relatively high compared to the rest. It's named "Messages" but it covers far more than just DMs.
I'm not an admin or really THAT technically knowledgeable when it comes to underlying infrastructure of these things, but because you mention VPN users in reference to shared IPs - would it be worth considering and mentioning mobile users or users otherwise on CGNAT networks?
For example, TMobile Home Internet would result in multiple users being represented by a shared public IP. Maybe these exit nodes don't have nearly the number of users under one IP in comparison to users behind a popular VPN services assigned IPs? I don't know, but thought it might be relevant! I understand it's also a tool geared toward combatting this spam and only so much can be considered against the improvement.
That's a consideration, yeah,, but they'd have to all be hitting lemmy.zip (your instance) and all from the same /32 IPv4 address.
(AFAIK) CG-NAT still uses port address translation so there's an upper limit to the number of users behind one IP address. They also are distributed geographically. So everyone would need to be in the same area on the same instance to really have that be an issue.
The more likely scenario would be multiple people in the same IPv4 household using the same instance. But 20 comments per minute, divided by two people in the house would still be 10 comments per minute. That's still probably more than they could reasonably do.
Edit: You mentioned T-Mobile internet. T-Mobile is pretty much all IPv6 with IPv4 connectivity via CG-NAT. lemmy.zip is also reachable over IPv6, so in that situation,it would try IPv6 first and CG-NAT likely wouldn't even come into play.
that makes sense! thanks for the break down, and good to know!
I never got IP-blocked by any instance.
One of these days your mom's gonna stop paying for your Mullvad subscription. Whaddya gonna do then?