using TCP53 for DNS

["Patrick W. Gilmore" <patrick () ianai net>]

In the thread about ns*.worldnic.com, many people were complaining  
about DNS responses/queries on TCP port 53.

At least one DoS mitigation box uses TCP53 to "protect" name  
servers.  Personally I thought this was a pretty slick trick, but it  
appears to have caused a lot of problems.  From the thread (certainly  
not a scientific sampling), many people seem to be filtering port 53  
TCP to their name servers.

Is this common?  Does anyone have stats on this (roots, GTLDs, other  
big name server farms)?  Perhaps people could send what they do  
personally and I can summarize for this list.  (Again, not a  
scientific sampling method, but better than trying to read into what  
people imply in a long, and probably not-well-read thread.)

--
TTFN,
patrick

P.S. Sorry to post operational content, I know how everyone hates  
that. =)