How can ethernet traffic be measured?

[Dan O'Neill]

Our site has about 55 hosts on a thin-net based lan.  Due to some
recent growth, I need a way to analyze the network traffic in order to
plan for the future.

The network is arranged in a star topology with some DEC ethernet
Mux's tying the whole thing together.  We have systems running under
Sun OS, Ultrix and MIPS OS.  We use NFS quite a bit as well as Yellow
Pages. 

I am not really familar with the traffic problems that occur on a
local area network and thus am not familiar with 'how much load is too
much load' type of evaluations.  I've seen Sun's 'traffic' program,
nice, but what does it all mean?

    What are the watermarks for network performance?

    How many collisions are too many collisions?

    Does UNIX provide any commands for gathering network performance
    statistics?

    Anyone know of any good reference material on the subject?

Thanks everyone!

-- 
Dan O'Neill                     Cadence Design Systems
dan at autosys.com                 San Diego, CA
{uunet|ncr-sd}!asihub!dan