Re: Intermittent network failure

[Jerry Draper <midrangel@xxxxxxxxxxxxx>]

We had a similar problem except that it wasn't CA dropping it was the i5 
itself.  We were configured at 100MB on the 400 and *auto on the switch.

IBM had us apply a series of microcode ptf's to the ethernet adapter. 
They recommended to put the i5 at *auto and the switch at *auto.

No problems since.

Jerry

PS:  Beware that power saving options can cause emulation drops so I 
leave "turn off disks" and "standby" at never.

J


Roger Vicker, CCP wrote:
> Before I spend $2000 for new switches (probably Netgear's Prosafe Smart
> Switch series) has anyone got any diagnostic hints on this problem.
>
> Model 800 at V5R3 with a Gigabit card (configured as 1G *FULL) to a SMC
> 6624M stacked switch's Gigabit port (configured as Auto-1000, the only
> Gigabit option). XP Pro PCs running Client Access Express (CAE)
> connected to the stack's 10/100 ports. New Cat5e patch cable tested with
> a medium-range network cable tester and installed for the Gigabit
> connection.
>
> Every day at least once, any CAE session that is actively talking at the
> wrong instant (not just sitting on a screen but sending/receiving) will
> fail.  The system doesn't log anything to Qsysopr and in fact thinks the
> session is still valid. The CAE session seems to freeze for about 5-10
> seconds then goes black and thinks it is disconnected. If you tell the
> CAE session to connect it gives an error that the device name is in use.
> The only solution is to wait until the TCP timeout expires (5 minutes)
> or to use another session to DSCJOB the interactive job attached to the
> session.
>
> The switch's event log shows nothing. The port counters show zero for
> any of the bad things like drops and errors.
>
> It can hit multiple PCs at the same time if they are at an active
> send/receive function.
>
> The time of day that it happens is not really predictable. Although it
> seems to cluster. Might hit for 5 minutes in the morning and not again
> till quiting time. It seems to only effect emulation (only protocol that
> is heavily used, no streaming audio/video...) but is not limited to IBM
> CAE as I am using Rumba and I get hit too. The one difference with Rumba
> (which does all communications through a single Engine) is that other
> sessions on the PC will usually go in to *DSC status automatically. Just
> the unlucky session that was talking at the wrong moment is left fully
> active on the system. The Rumba Engine reports a communications error
> and shuts down. Once the falsely active session is cleared all the Rumba
> sessions and Engine connect like normal.
>
> Thanks.
>
> Roger Vicker, CCP