Blocked IP Double

Hi @dimalifragis, thanks for reaching out to us about this.

Getting caught by “Page not found errors limit for humans” could be because your Rate Limiting settings are very strict. I generally set my Rate Limiting Rules to these values to start with:
Rate Limiting Screenshot

• If anyone’s requests exceed – 240 per minute
• If a crawler’s page views exceed – 120 per minute
• If a crawler’s pages not found (404s) exceed – 60 per minute
• If a human’s page views exceed – 120 per minute
• If a human’s pages not found (404s) exceed – 60 per minute
• How long is an IP address blocked when it breaks a rule – 30 minutes

I also always set the rule to Throttle instead of Block. Throttling is generally better than blocking because any good search engine understands what happened if it is mistakenly blocked and your site isn’t penalized because of it. Make sure and set your Rate Limiting Rules realistically and set the value for how long an IP is blocked to 30 minutes or so.

Remember there is no hard and fast, one size fits all set of rules for every site. This is just a good place to start. During an attack you may want to make those rules stricter. If you see visitors, like search engine crawlers getting blocked too often, you might want to loosen them up a little.

Here is a video guide to Rate Limiting as well:
Rate Limiting Guide

Let me know how you get on!

Thanks,

Mark.

Hi @dimalifragis, thanks for getting back to us.

Would you please share the screenshot once again as we are not able to see it? Looks like you have already deleted it. 

Thanks,

Mark.

Hi @dimalifragis, Thank you for sending the screenshots and apologies for the delayed response.

I have confirmed that this is a racing issue. It happens if the hits are coming in fast and in parallel, and the server is fast enough to process them in parallel.

It looks like  some of the hits were happening so close together that when Wordfence checks the rate limit, just before the limit is hit, a few of the hits see that the rate limit has not been hit yet — but each of them count as the first hit that should be blocked, so they add a block record.

This is unavoidable without adding a locking mechanism, which would slow down the site in order to avoid timing issues from overlapping hits, so this is expected behavior. Since these blocks are not permanent, they will all be removed when they expire.

Thanks,

Mark.