On Mon, 24 Feb 2020, Robert Armstrong wrote:
   FWIW, I think the "flapping" is a Multinet
problem.  I have no problems
 with simh and DECnet connections over the local Ethernet. 
I'm not doubting you, but I'm not sure about that.
Even the connection from FRUGAL and MISER flap with the circuit to 31.3:: 
turned off.  That's just DECNET to my knowledge.
For the record, the circuits to LEGATO and MIM do not flap.  It's very 
odd.
Upgrading SIMH was on my consideration list.   I may try this.
Thanks everyone for the tips so far.
Supratim: I do not have SIMH nice'd down - just have CPU idle set.   Not 
to be "that guy" (I hate it when users do this, so I hesistate to say 
this) but on my other host system (probably running an even older version 
of SIMH) it did not flap this badly.
(more messages to wade through ....)
Fred