[nsp] xmodem transfer fails with "No ACK on EOT"

[Sam Stickland]

Gert Doering <gert at greenie.muc.de> wrote:
> Hi,
>
> On Sat, Apr 03, 2004 at 11:49:24PM +0100, Sam Stickland wrote:
>> Has anyone got any idea why an xmodem transfer of an IOS image would
>> progress all the way to the end and then say "No ACK on EOT". This
>> is using minicom with lrzs 0.12.20 onto a Cisco 3640 in rommon mode.
>
> Without knowing details, I'd assume that it's a different
> interpretation of the xmodem "standard".
>
> Later versions of xmodems require that the final packet is ACKed
> twice, to cope for potentially garbled bytes that are mistaken for an
> EOT ("end of transmission") packet.  Earlier versions send only one
> ACK, and then the receiver exits.
>
> If that theory is true :-) your xmodem upload will actually work, even
> if minicom complains about it.

Unfortunately the router does nothing until I press return and then it
responds 'command "......." not found'. Nothing gets written to the flash.
'dir flash:' only shows the old image (marked as deleted).

Thanks for your help though. Fortunately this has ceased to be a priority
since another 3640 (with more flash and RAM in it) has arrived. Now I have
more time on my hands I'm gonna try it with an old version of Hyperterminal
at my leisure (seeing as that's the example program on the cisco site).

Sam