ku_fastsend ethernet blocking

[Robert Evans]

A week after upgrading to Ultrix 4.1, we started getting the follow error:

----- EVENT INFORMATION -----

EVENT CLASS                             OPERATIONAL EVENT
OS EVENT TYPE                  250.     ASCII MSG
SEQUENCE NUMBER                143.
OPERATING SYSTEM                        ULTRIX 32
OCCURRED/LOGGED ON                      Sat Apr 27 11:48:36 1991 WET DST
OCCURRED ON SYSTEM                      v1
SYSTEM ID                 x05903B14
PROCESSOR TYPE                          KA825
PROCESSOR COUNT                  2.
PROCESSOR WHO LOGGED      x00000002
MESSAGE                                 ku_fastsend: transmit failed on de0,
                                         _errno 55

The message repeats every time something tries to access the network so all
network access is blocked.

The system is an 8350 with a DEUNA on the UNIBUS.

Field Service have (i) suggested that we are running out of mbufs and that this
can be increased by upping MAXUSERS.   So we put it up to 256 with no effect.
(ii) changed the DEUNA (still no good). (iii) had me patch vmunix to change
ifmaxqlen to 250 (ifmaxqlen is defined in if.o).

But the problem still occurs.  Anybody come across this before.  Is there a
known fix that works?

Our configuration is as follows:

ident           "V1"
machine         vax
cpu             "VAX8350"
maxusers        256
processors      2
maxuprc         50
physmem         26
timezone        0 dst 3
smmax           256
smseg           12
smbrk           1024

options         QUOTA
options         INET
options         NFS
options         RPC
options         UFS
options         SMP
options         SYS_TRACE
options         PACKETFILTER

... then the device info ...

scs_sysid        1

pseudo-device   pty 64
pseudo-device   loop
pseudo-device   ether
pseudo-device   inet
pseudo-device   nfs
pseudo-device   rpc
pseudo-device   ufs
pseudo-device   sys_trace
pseudo-device   packetfilter

(The one other difference between this Ultrix and the last version 4.0 on I ran
is the packetfilter stuff which I've added for nfswatch.  I haven't run
nfswatch though).
--
  Robert Evans, Dept of Computing Maths, University of Wales College of Cardiff,
  PO Box 916, Cardiff, Wales, UK, CF2 4YN.  Tel: +44 (0)222 874000 x 5518
  Internet: R.Evans%computing-maths.cardiff.ac.uk at nsfnet-relay.ac.uk
  UUCP:     R.Evans at cf-cm.UUCP or ...!uunet!mcsun!ukc!cf-cm!R.Evans
  Janet:    R.Evans at uk.ac.cardiff.computing-maths