Problem thru Sonicwall -- FTP and email downloads fail.

I have been two weeks with Sonicwall "support" on some issues with a TZ170 and no resolution!

When my customer tries to download multiple files from FTP the download hangs in the middle of a file, after a few files clear.

Same with email messages.

What could be the problem?

We are on a cable modem; swapping in the old Linksys "router" resolves all the problems instantly. We use Intrusion Prevention, Content Filtering, and Gateway Antivirus, Disabling antivirus and Intrusion Prevention makes no difference.

We tried adjusting MTU, packet fragmentation permission, FTP rule (we are downloading from the Web, but anyway put in a rule...), some exotic settings about FTP attacks, etc.

There must be some generic issue here. Or a problem in the pass-through of multiple distince files.

Thanks for any insight.

Richard B

We did try all the obvious things like Passive vs Active FTP. No change.

By the way we are using WS_FTP95. As I said, it works fine with the Linksys (old) router.

Thanks.

Richard B.