Odd FTP upload Issue through PIX.

[lowell.stewart]

I'm having a strange issue when uploading very specific files (ONLY .CSV) through my PIX firewall. For whatever reason, only this file format fails when users upload to any FTP site, and it always fails after about 65000(+/-) bytes. Renaming the file doesn't matter so it has something to do with the actual format and not the mime extension.

I've got a PIX520 running version 6.3(4) and my edge router is a 2600 running 12.3.14(T4). If I FTP Internally accross my WAN, the problem doesn't occur, only when traversing my PIX and edge router out to the Internet.

Thanks.

[mpalardy]

Check for source port (>1024) and if this port hits one of those configured with fixup protocol on the pix. You may do a show fixup command on the pix to display witch ports are inspected.