With a kernel built with sources grabbed after Friday's supscan,
I can now fairly reliably deliberately trigger a locked up interface
that requires ifconfig ep0 down ; sleep 1 ; ifconfig ep0 up
to unstick TCP connections through that interface.   This
happens whenever I do large amounts of I/O, most notably
when I copy alot of data from cd0 to sd0.

It is particularly likely to happen as a burst of traffic
arrives on the interface.

Unfortunately the locked-up interface problem happens non-
deliberately also.

This is something that has gotten much worse over the past
couple of days of -current, to the point where I either need
to revert, or maintain a script that does an ifconfig up/down
every couple of minutes if I'm doing significant disk or CD i/o.

 -current syssrc from the 20th, with the same config,
does not have this problem.  

	Sean.

NetBSD 1.4M (SMDCRIPPLE) #0: Sun Oct 31 12:33:30 GMT 1999
    root@:/usr/src/sys/arch/i386/compile/SMDCRIPPLE
cpu0: family 5 model 4 step 3
cpu0: Intel Pentium/MMX (586-class)
total memory = 97920 KB
avail memory = 78820 KB
using 2822 buffers containing 14688 KB of memory
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o enabled, memory enabled
pchb0 at pci0 dev 0 function 0
pchb0: VIA Technologies VT82C580 (Apollo VP) Host-PCI Bridge (rev. 0x23)
pcib0 at pci0 dev 7 function 0
pcib0: VIA Technologies VT82C586 (Apollo VP) PCI-ISA Bridge (rev. 0x27)
pciide0 at pci0 dev 7 function 1: VIA Technologies VT82C586A IDE Controller
pciide0: bus-master DMA support present
pciide0: primary channel configured to compatibility mode
pciide0: disabling primary channel (no drives)
pciide0: secondary channel configured to compatibility mode
pciide0: disabling secondary channel (no drives)
isp0 at pci0 dev 8 function 0
isp0: interrupting at irq 11
isp0: Ultra Mode Capable
isp0: Board Revision 1040B, resident F/W Revision 4.50.0
isp0: Last F/W revision was 4.50.0
isp0: 249 max I/O commands supported
isp0: driver initiated bus reset of bus 0
scsibus0 at isp0: 16 targets, 8 luns per target
ahc0 at pci0 dev 9 function 0
ahc0: interrupting at irq 11
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
scsibus1 at ahc0 channel 0: 16 targets, 8 luns per target
vga1 at pci0 dev 10 function 0: Matrox MGA Millennium II 2164W (rev. 0x00)
wsdisplay0 at vga1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-3 added (80x25, vt100 emulation)
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37b irq 7
pckbc0 at isa0 port 0x60-0x64
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pmsi0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
wsmouse0 at pmsi0 mux 0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: PC speaker
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
isapnp0: read port 0x203
isapnp0: No current device for tag, card 1
sb0 at isapnp0 port 0x220/16,0x330/2,0x388/4 irq 5 drq 1,5
sb0: Creative SB AWE64  PnP Audio: dsp v4.16
audio0 at sb0: full duplex
mpu0 at sb0
midi1 at mpu0: SB MPU-401 MIDI UART
opl0 at sb0: model OPL3
midi2 at opl0: SB Yamaha OPL3
isapnp0: <Creative SB AWE64  PnP, CTL7002, PNPB02F, Game> port 0x200/8 not configured
isapnp0: <Creative SB AWE64  PnP, CTL0022, , WaveTable> port 0x620/4 not configured
ep0 at isapnp0 port 0x210/16 irq 9
ep0: 3Com 3C509B EtherLink III 
ep0: address 00:10:4b:7a:0e:1f, 8KB byte-wide FIFO, 5:3 Rx:Tx split
ep0: 10baseT (default 10baseT)
biomask ed45 netmask ef45 ttymask ffc7
scsibus0: waiting 2 seconds for devices to settle...
sd0 at scsibus0 targ 0 lun 0: <IBM, DDRS-39130W, S97B> SCSI2 0/direct fixed
sd0: 8715 MB, 8387 cyl, 10 head, 212 sec, 512 bytes/sect x 17850000 sectors
isp0: Bus 0 Target 1 Async Mode
sd1 at scsibus0 targ 1 lun 0: <IBM, DGHS09U, 0350> SCSI3 0/direct fixed
sd1: 8748 MB, 8152 cyl, 10 head, 219 sec, 512 bytes/sect x 17916240 sectors
isp0: Bus 0 Target 2 Async Mode
sd2 at scsibus0 targ 2 lun 0: <IBM, DGHS09U, 0350> SCSI3 0/direct fixed
sd2: 8748 MB, 8152 cyl, 10 head, 219 sec, 512 bytes/sect x 17916240 sectors
scsibus1: waiting 2 seconds for devices to settle...
ahc0: target 4 synchronous at 20.0MHz, offset = 0xf
ahc0: target 4 Tagged Queuing Device
sd3 at scsibus1 targ 4 lun 0: <MICROP, 3391SS, p43D> SCSI2 0/direct fixed
sd3: 8681 MB, 4811 cyl, 22 head, 167 sec, 512 bytes/sect x 17780058 sectors
ahc0: target 5 synchronous at 10.0MHz, offset = 0xf
cd0 at scsibus1 targ 5 lun 0: <TEAC, CD-R55S, 1.0K> SCSI2 5/cdrom removable
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
boot device: sd0
root on sd0a dumps on sd0b
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
isp0: Bus 0 Target 0 at 20MHz Max Offset 8, 16 bit wide, Tagged Queueing Enabled
root file system type: ffs
wsdisplay0: screen 4 added (80x25, vt100 emulation)
wsmux1: connecting to wsdisplay0