[j-nsp] OP script - failing to download code image

[William McLendon]

hi all,

we have a home-grown OP script that we use to bulk upgrade EX switches for new deployments.  New switches come out of the box (lately on 11.4R1) and the script executes and auto-upgrades the switch to 11.4R5 or 11.4R6 (tested fine with these).

I have been trying to update the script to update to a 12.x image (have tried 12.2R4 and 12.3R2) and the script executes and begins downloading the image, however Wireshark traces show that the switch sends a FIN/ACK to the FTP server before it has completed downloading the image.  This in turn causes the file download to fail, and the upgrade does not occur.

I have tried a different FTP server and still see the same behavior; if I revert back to the old script it works as expected.  The only difference I can think of is that the image of 12.2 and 12.3 are a little bigger than the 11.4 image, and i'm possibly running into some kind of timeout or hard-coded filesize limit that an Op script is allowed to download.  Is anyone aware of such a thing, or have any other ideas why the switch would be prematurely terminating the FTP session?  I have confirmed that there is ample storage space on the box -- if I run the CLI equivalent of what the Script executes (file copy src dst) the image downloads without issues from the FTP server.

Thanks,

Will