The up­date of the Mul­ti­ping mo­du­le for Dru­pal is now avail­able on this site! I've been run­ning it for three weeks now and it didn't cause any trou­ble, so I hope it will work fine on your site(s), too.
I've been ex­pe­ri­en­cing some track­back spam floods re­cent­ly, so I'm try­ing some new means of fil­te­ring:

• The ser­ver men­tio­ned in the track­back link must re­sol­ve to an IP in the same sub­net as the IP sen­ding the track­back
• The page to which the track­back link re­fers must con­tain the URL of my site

Plea­se help me tes­ting this sche­me: Write a blog entry with a link to my page, and send a track­back here. If the track­back doesn't get through, plea­se drop a com­ment here. I'm cu­rious whe­ther this will work...