I'm not convinced this is a real concern. Bots, maybe, but then again even fancy analytics will be fucked by that because they use hundreds or thousands of high-reputation residential IPs. So, you're optimizing for the wrong thing I think.

No, you don't need consent for that. It falls under the legitimate interest exception.

You need to disclose it in your privacy policy, you need to delete it after a reasonable retention period and you can't use those logs for other purposes like ad targeting, but you don't need a consent banner to track things that you are legitimately using for security purposes.