Thread:Project:Support desk/Easy way to implement massive IP range blocks?/reply

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.