On Apr 10 (this Monday), SUNET's  backup server was reconfigured to run a
maximum of  two parallel backups over  our main ethernet, rather  than as
many  as the  ethernet would  take.  I believe  this to  have solved  the
duplicate problem by  preventing the ethernet from  getting saturated and
triggering  a link  flap  which  in turn  may  trigger duplicate  copies,
normally with  an incidence of 1  in 10,000 (naturally if  the duplicated
message goes to 200 users, 200  extra copies are generated). At any rate,
there has  been no  link flap  between SEARN  and SEGATE  since Apr  9 at
around 9pm  local. If  there are  still duplicates, it  means there  is a
second problem.
 
If any of you have received  duplicates bearing a "Date:" field that says
Apr 10 or later (Swedish time in  case your mail system adjusts for local
time), please notify me *in private*. Again, the date that matters is the
date  the message  was distributed  to  the list,  and not  the date  you
received it. Finally, if you were  thinking of flaming me or pointing out
that messages shouldn't be duplicated  when a connection goes down, well,
I agree. The people who designed the  protocols made a mistake a there is
a time window  where the receiving site has accepted  the message but the
sending site thinks  the transfer was aborted because  the connection was
lost. I did not design these protocols,  and I did my best to address the
problem as soon as it was reported.
 
  Eric