Subject: Re: kern/29971: Loopback checksum optimizations cause UDP problems
To: None <gnats-bugs@netbsd.org>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: netbsd-bugs
Date: 04/15/2005 11:44:44 
> >Number:         29971
> >Category:       kern
> >Synopsis:       Loopback checksum optimizations cause UDP problems

did you try this?
http://mail-index.NetBSD.org/tech-net/2005/01/20/0000.html

YAMAMOTO Takashi