In the LISTSERV 1.7 release notes Eric says:
 
                                                    Combined  with the  new
  DISTRIBUTE path  generator (qqv), the ability  to enter new links  in the
  LISTSERV configuration  without having  to alter  BITEARN NODES  makes it
  possible to assess the impact of major network changes in advance (before
  the NODUPD files are released) and  avoid the all too frequent "emergency
  LINKSWT shipment" following a BITEARN NODES update.
 
How do I do this?  I'd like to be able to see what various link speeds
on redundant paths will do to DIST processing.  A 2-minute peak at
LISTSERV 191 was uninformative (which doesn't mean the necessary hints
aren't there--I just didn't find them).
 
--Brick