Hiya.  I think you may be somewhat misunderstanding
the /net directory ....

What happens, is when a node boots, and qnet (and
a network driver) starts, if that node is quiet - 
ie there are no applications on it which try to
communicate to other nodes via qnet - is that the
/net directory is slowly populated, by the rest of
the qnet nodes who occasionally broadcast their
node info.  The default time interval for this is
30 seconds, and is controlled by the "auto_add=X"
command line option to qnet.  So, 30 seconds
after booting, /net is probably as full as it's
going to get.

But you don't have to wait 30 seconds to talk
to a remote node - immediately after qnet and
the network driver initialize, an application
on your node may attempt to communicate with
a remote node via qnet.

I don't think you want to have all the nodes
broadcasting their info every 50 milliseconds,
but I suppose you could on a very small network,
as long as you were willing to absorb the loss
of usable network bandwidth and the increased
cpu consumption for all the received packets.

When there is an entry in the /net directory,
all it means is that qnet now has a mapping
for an (ascii text) node name, to an ethernet
mac address.  It speeds up the node resolution
process ever so slightly, and is convenient
for people to see what other nodes MIGHT be
on the network.

Important point here: entries in /net are NOT
deleted, until someone tries to use them, and
they are found to be invalid.

For example, someone might have booted a node
an hour ago, run it for a minute, then shut
it down.  It will still have an entry in the
/net directories of the other qnet nodes, 
if they never talked to it.  If they did talk
to it, and establish session connections,
everything will eventually be torn down as
the session connections time out.

If you look at the usage message for qnet,
it can be configured pretty any way you
want it to be.  Just be sure that you understand
the consequences of your changes on the
network bandwidth and cpu consumption.

A couple of hints on /net ...

Here is a good way to flush out invalid
entries from /net:

  # ls -l /net &

Here is a good way to completely clean out /net

  # rmdir /net/*

--
aboyd