# ISP-based anti-spam countermeasures **URL:** \ **Category:** Feature\ **Created:** [9월 15, 2014, 5:41오후 UTC](https://meta.discourse.org/t/isp-based-anti-spam-countermeasures/20082 "2014-09-15T17:41:36Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![callmevlad](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/callmevlad/32/114850_2.png) [@callmevlad](https://meta.discourse.org/u/callmevlad)\ **Post date:** [9월 16, 2014, 5:35오전 UTC](https://meta.discourse.org/t/isp-based-anti-spam-countermeasures/20082/3 "2014-09-16T05:35:00Z")
Good point, I wasn’t actually aware that we could block entire ranges, so great to know! Thanks Jeff! 😃 We are certainly banning each spammer’s IP address, but they use a different one every time - banning ranges makes a lot more sense. Initially, we wanted to be as permissive as possible, without leaving out possible legitimate users from those ISPs - but that’s less and less of a concern. For those wondering how this is done, you can block ranges of IPs like this: 39.36.108.135 39.36.192.11 39.36.195.54 39.36.195.54 39.36.214.120 39.36.217.148 39.36.217.154 39.36.227.212 By entering “39.36.0.0/16” here: ![](https://global.discourse-cdn.com/meta/original/3X/4/d/4ded5ad00b89e673cf706d8ecdf771a53eaa3452.png) This tool is useful for converting a start/end IP range into a CIDR which Discourse expects: [http://www.ipaddressguide.com/cidr#range](http://www.ipaddressguide.com/cidr#range) --- _[View the full topic](https://meta.discourse.org/t/isp-based-anti-spam-countermeasures/20082)._