[ILUG] Why stop networking at shutdown?

[Kenn Humborg]

Today I was playing with a UPS with a network card.  I've configured
apcupsd and the UPS to communicate via the network and it works quite
well.  Except for the bit where the machine tells the UPS to power 
down at the end of the shutdown sequence...

See, by the time rc.d/halt runs, networking has been shut down, so
there is no way to talk to the UPS.

So, that got me thinking...  Why is networking torn down at shutdown
at all?  Would it not be useful to keep ethernet interfaces up and
a routing table in place?  This is a RHEL4 clone, but I'm aware
that RH-derived systems have been doing this for ages.  Was it
always this way?  Do other Linuxes leave networking up?  Do other
Unixes leave networking up?

Later,
Kenn