[comp.unix.aix] Ethernet adapter problems

scott@prism.gatech.EDU (Scott Holt) (10/31/90)

We have a number of RS 6000s connected to our campus network -
a network which sees quite a bit of traffic. From time to time,
the ethernet interfaces in the machines will simply shut off.
One machine, a model 540, seems to have a particularly bad time
of it. It comes up just long enough for routed to learn a few
routes and then shuts off. Actually, it looks like the machine
receives just fine, but cannot send.

The following errors are logged with each attempted outbound packet:
	CMSA/CD LAN COMMUNICATIONS LOST
 and    COMMUNICATION PROTOCOL ERROR

The cabling checks out ok and the card passes diagnostics.

Any clues? Has anyone else had trouble with ethernet interfaces
shuting down under high traffic conditions. I might add, a significant
part of the traffic on our network is broadcast traffic generated
by various terminal servers.

- Scott

brian@electra.la.locus.com (Brian D. Horn) (10/31/90)

In article <16128@hydra.gatech.EDU> scott@prism.gatech.EDU (Scott Holt) writes:
>
>We have a number of RS 6000s connected to our campus network -
>a network which sees quite a bit of traffic. From time to time,
>the ethernet interfaces in the machines will simply shut off.

	Note: I haven't seen this on a 6000, but odds are good that what
I have to say follows.

	On EVERY piece of hardware using the Intel 82586 I have found
that the chip gets itself wedged into an "impossible" state under conditions
of heavy traffic, especially broadcast traffic.  I have seen this in
at LEAST 5 different hardware platforms INCLUDING one built by Intel.
The only solution I have seen is having the device driver have a watchdog
timer check for such a condition and pull on the reset line if and when
the condition is detected and restart the I/O.