Network Mangement

[Charles Hedrick]

It's a bit unusual to have any significant CRC errors on an Ethernet.
You might want to look at collision rates (given by netstat), as that
will tell you if your network is approaching saturation.  (Should be
at most a few percent.)  However it is probably better if you have
serious monitoring tools such as the various Ethernet tools present in
Sun's release 3.0.  Also watch the performance of your gateways.
Normally these are the bottlenecks in the system, and many TCP
implementations can't deal well with slow gateways.  I don't know any
of the machines you are using, so I can't comment on them.  But I can
say that we have had to do serious work on some TCP's to get them to
handle slow gateways.  Beware that repeaters and Vitalink things give
you a single logical Ethernet.  Protocol incompatibilities or a
program that has a bug that causes it to generate lots of broadcasts
can bring down the whole network.  I strongly suggest using real IP
gateways at a number of places in your network, just to provide
isolation.  Particularly use them between parts of the network under
different management, and between student and research parts.  Having
a repeater or protocol-independent gateway connecting you to a network
over which you have no control is asking for trouble.