I havent been really paying attention to this thread, but
maybe increasing the value of kern.mbuf.nmbclusters with sysctl -w might
fix the problem.  Or you might want to recompile your kernel with a higher
value for NMBCLUSTERS.

On Sun, Jun 24, 2001 at 01:15:58PM -0400, Kevin P. Neal wrote:
> On Sat, Jun 23, 2001 at 08:30:59PM -0400, Brad Spencer wrote:
> > One potential reason for this is an overloaded ppp link.  This plagued me
> > when a 28.8 async. ppp link was my only connection to the Net.
> > 
> > What I think occurs is that there is so much backed up traffic waiting to
> > go out the pipe that the system runs out of space.  This effects UDP and
> > ICMP traffic the most.
> 
> Which is totally unacceptable. 
> 
> It seems unreasonable for the link to become so backed up that nothing
> can ever be sent out of it again (until it is bounced). 
> 
> Why can't it drop data with 'no buffer space' errors while it tries to
> send what it does currently have in buffers?
> -- 
> "A method for inducing cats to exercise consists of directing a beam of
> invisible light produced by a hand-held laser apparatus onto the floor ...
> in the vicinity of the cat, then moving the laser ... in an irregular way
> fascinating to cats,..." -- US patent 5443036, "Method of exercising a cat"