🚀 go-pugleaf

I'm not sure if this is the correct Bboard for this.  If not,
please let me know where it should be sent.

We have an ethernet which consists of 5 VAX 750s plugged into a DEC
Delni.  This is connected onto a length of cable which has 4 other
Int. Sol. machines and 2 suns.  We just recently ran about 500 ft. of
cable (which together with the already existing cable placed us
around 300 meters or so) and moved 2 of the Int. Sol. machines to the
end of this length. (All systems are running 4.2BSD [Suns run SUN's
version]) Basically our configuration looks like this:

A  B  C                          +-- added length --+
 \ | /                           V                  V
 delni ----------Sun--Sun--IS--IS--------------IS--IS
 / | \                                         (x) (y)
D  E  IS

About a week or so after this change was made we started having
problems. About every 2-4 weeks suddenly every machine on the net
claims that every other machine is down.  You can't connect to any
other machines.  I have found that if I disconnect the extra length
(recently added) the problem seems to go away. It would seem to not
be a bad ethernet board in one of the machines because I can connect
either one of the 2 IS's ('x' or 'y') onto the net by itself and the
net is still upset. However, I can reconnect the extra length (along
with the 2 machines at the end of it) after about 15-30 min's and
everything is fine for another few weeks.  Sometimes the problem
seems to just goes away on its own also!  (By the way, a "netstat -i"
says we are sending and receiving lots of packets but getting about
as many input errors as input packets!)

Has anyone ever seen anything like this?  I'm guessing it means we're
too close to the max. length for the ethernet, but I calculate the
total length as around 300 meters and the standard say 500 meters.

------------------------------------------------------------------------
Richard Johnson                             raj@uci.edu           (ARPA)
UCI ICS Research Systems Manager            ucbvax!ucivax!raj     (UUCP)