[mod.computers.vax] microVMS 4.4, DECnet 4.4 and DEQNA's

cetron%utah-cbd@UTAH-CS.ARPA.UUCP (06/10/86)

	I recently brought up uVMS 4.4 with no apparent trouble on
my MVII.  All seems well except the DECnet keeps going up and down
every 7-12 minutes....messages like:

	DECnet event 4.7, circuit down, circuit fault
	...
	Circuit QNA-0, Line synchronization lost


	DECnet event 4.10, circuit up
	...
	Circuit QNA-0

	
and this repeats roughly 4-6 times and then stays up for 7-12 minutes....
over the weekend I produced 120 pages of OPCOM messages....I have since
turned off monitor logging of events 4.7 and 4.10 and the system seems
more robust (it stays up 10-15 minutes now)....

	The afflicted MVII connects into a DELNI with another MVII running
4.2, an 11/44 running RSX-11M+ DECnet, an 11/73 MINC  running RSX-11M+ DECnet
as well as a 750 and an HP bobcat running TCP/IP. Then DELNI then connects into
a larger TCP/IP speaking ethernet... None of the UNIBUS machines show any line
synchronization problems.  The 11/73 MINC (with a DEQNA) shows no problems. The
other MVII  running uVMS 4.2 shows roughly 2-4 cycles per day of this same 
pattern.

	Has anyone else noticed this problem?  Is it hardware? or the new 4.4?

-ed		cetron%utah-cbd@utah-cs.arpa

dolson@USC-ISIF.ARPA.UUCP (06/11/86)

ed-

I had a similar problem with circuit drop/reappearances when I first
set up our ethernet just a few months ago.  I was taking a single
11/785 to a two-node (both 11/785s) VAXCluster.  With no ether
experience we were trying to bring up DECSA terminal servers (which
get their load software from any host-designated VAX on the ether),
the DEUNAs on the VAXen, and interconnecting these boxes with a DELNI.
As you experienced, we saw circuit yo-yos which made absolutely no
sense.  At times things were so confused that the DEUNA on the first
785 looked like it had completely died; NCP> was reporting hard
controller errors, etc, which didn't go away until rebooting.

What was getting us was the DELNI.  It has 8 ports, right?  logically
equivalent, right?  Evidently not electrically.  If you aren't using
all 8 ports, start your connections at port 1 (nearest the special
DELNI-DELNI port) and use them sequentially.  I only counted 7
connections in your message so if your vacant DELNI port isn't number
8, maybe it should be.  That cleared our problems up.  And trying it
should only take a minute or two.

Doug (dolson @ Ada20.arpa)
-------

rick@NGP.UTEXAS.EDU (Rick Watson) (06/12/86)

DEQNA's have some kind of problem with collisions which make them
almost unusable on an ethernet that is any more than very lightly
loaded.  There is an ECO due out now to cure the problem.  My 
field service rep told me that he hoped to be able to order it soon.
You may have to badger them a bit to find out much about it as it
(the ECO) is still in the process of being released.

Rick Watson
University of Texas Computation Center
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