  DECnet LINKABORT errors; packet collisions? 
 The Question is:
 
We have a VAX 7860 running 6.2 and an Alpha 4100
running 6.2-1H3.  Both are using DECnet IV.
 
Intermittenly, when accessing files on the Alpha
from the VAX over DECnet, we encounter the
following error:
 
%TYPE-W-READERR, error reading ADMAX1::D1:[TEMP]A.LOG;4
-RMS-F-SYS, QIO system service request failed
-SYSTEM-F-LINKEXIT, network partner exited
%TYPE-W-CLOSEIN, error closing ADMAX1::D1:[TEMP]A.LOG;4 as input
-RMS-F-WBE, error on write behind
-SYSTEM-F-LINKABORT, network partner aborted logical link
 
The line counter on the VAX is as follows:
 
        7561  Seconds since last zeroed
      604408  Data blocks received
       34183  Multicast blocks received
         371  Receive failure, including:
                Frame too long
   136119604  Bytes received
     2700717  Multicast bytes received
           0  Data overrun
      635141  Data blocks sent
        3776  Multicast blocks sent
        2229  Blocks sent, multiple collisions
        1954  Blocks sent, single collision
        2491  Blocks sent, initially deferred
   149094526  Bytes sent
      395512  Multicast bytes sent
           0  Send failure
      &gt;65534  Collision detect check failure
         371  Unrecognized frame destination
           0  System buffer unavailable
          11  User buffer unavailable
 
And the line counter on the Alpha is as follows:
 
      &gt;65534  Seconds since last zeroed
     8090015  Data blocks received
      184059  Multicast blocks received
        5483  Receive failure, including:
                Block check error
                Framing error
   908085207  Bytes received
    12451483  Multicast bytes received
           0  Data overrun
     8982148  Data blocks sent
        4696  Multicast blocks sent
           0  Blocks sent, multiple collisions
           0  Blocks sent, single collision
           0  Blocks sent, initially deferred
  3555041617  Bytes sent
      192240  Multicast bytes sent
           2  Send failure, including:
                Carrier check failed
           0  Collision detect check failure
           0  Unrecognized frame destination
           0  System buffer unavailable
           0  User buffer unavailable
 
We have checked the hardware and it seems OK.
Could it be related to the executor settings
or the process quota?
 
 
 The Answer is:
 
  If you have 7561 seconds since last zeroed -- that's about two hours --
  and of 635141 data blocks traversing the VAX, the VAX system encountered
  problems sending 6674 of these blocks -- 2229 blocks deferred due to
  multiple collisions, 1954 blocks defered due to single collision, and
  2491 blocks sent that deferred before sending, your network appears to
  have a problem -- these values tend to indicate your network is jammed.
  Contrast this with the Alpha, where no problems were encountered.
 
  The OpenVMS Wizard would recommend checking the VAX 7000 model 860 LAN
  network segment and the network controller for potential problems.
  Check for poor or missing termination, faulty LAN cables, incorrect
  LAN wiring, and similar problems.
 
  Also check to see if the transceiver heartbeat is set appropriately,
  with the appropriate cabling used -- there is an unusually large value
  for the number of collision detect check failures.
 
  Further, check the OpenVMS Alpha system, as it is possible that the
  network controller is triggering the problem with the OpenVMS VAX
  controller -- one potential cause of this behaviour is a network
  controller set to full-duplex operations on a half-duplex circuit.
 
  The user buffer unavailable count value indicates that the applications
  are occasionally getting bogged down, and not responding.  (See the SDA
  command SHOW LAN/COUNT to try to track this application down.)
 
  If you are unable to locate the cause, please contact your hardware
  support organization.
 
 
