I'm running a very small wiki. I'm having some problems with spammers. I have a hosting package with another company which may limit to some degree what I'm capable of doing. Geolocation tools say that the spammers are virtually all coming from a specific part of China, but the "real" users of the wiki are only from a specific bit of Southern California, so I'd kind of like to block write permission (or block account creation) for all of the world except for the US. Apparently, this would mean a set of IP range blocks something like the following: 217.0.0.0/8 218.0.0.0/7 220.0.0.0/6 224.0.0.0/3 but the Mediawiki interface will only let me do /16 IP range bans, which would be an incredible amount of range bans. Any suggestions on how to stop these spammers from creating user accounts without mandating that every "good" user account be individually vetted and allowed to come on board?
Topic on Project:Support desk
Manual:$wgBlockCIDRLimit, but you can do little unless you can get this changed in your LocalSettings.php.
On the subject of Chinese spam, unfortunately there's great danger for collateral damage unless you have no Chinese users and don't expect any. Also, you shouldn't be getting any edits from 224.0.0.0/3 at all - your ISP should be discarding packets from those addresses.
Thanks. If I change the setting in LocalSettings after the block has been set, does the fix stay in or does it get lost? In other words, having now blocked 217.0.0.0/8, 218.0.0.0/7, and 220.0.0.0/6, if I set LocalSettings back to the way it was, will those range blocks still stay blocked?. What sort of collateral damage might occur (I have no Chinese users and don't expect any)?
I don't know about that.
If you have no Chinese users and don't expect any, you should be fine.