[bitfolk] Troublesome activity

My VPS is receiving 250 connections per second from an IP 51.81.86.37.  This started yesterday evening.  I've no idea who is doing it or why. The logfiles are filling up as fast as I can delete them, but my website keeps falling over as all the disk space has been filled. Sample from syslog: Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#44122 (.): query (cache) './ANY/IN' denied Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#44122 (.): query (cache) './ANY/IN' denied Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#17043 (.): query (cache) './ANY/IN' denied Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#17043 (.): query (cache) './ANY/IN' denied Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#17043 (.): query (cache) './ANY/IN' denied Jul 24 12:39:52 buddhismwithoutboundaries named[629]: client 51.81.86.37#17043 (.): query (cache) './ANY/IN' denied The IP belongs to a cloud hosting service, OVH.  I've written an email to abuse(a)ovh.ca, but I don't hold out much hope of them sorting it out. Does anyone have a suggestion for how I should proceed? Ian.