FTP Upload - Big Problem!

[Klink]

REngles,

I'm titillated to hear your continued interest in this issue, and the few hours I spent researching and conducting my previous tests have not gone in vein.

I'm a big believer in simplifying a test scenario to troubleshoot a problem. This ftp issue gets a bit complicated when the introduction of router filters, and proxies are introduced into the equation (let alone changing the network layer as in PPPoE). I propose we look at this with a bit more focus on the one issue, the ftp protocol and how Mac OS X does or doesn't work with this in a controlled test bed.

I have at my disposal an ftp server in which I have full control (Using AppleShareIP 6.x. Don't laugh please. Ostensibly seen as a unix ftp server from the outside.) I also have the ability to run my OSX 10.1 machine on the servers local net (on the same switch) with the only addition of my ISP supplying routing for this net. If I conduct another test, using only Terminal and it's ftp application as the client (only because I have utmost control of the protocol settings and there validity), use tcpflow as my monitoring source and capture the results of both active and passive ftp sessions, perhaps we can look at the results and come to an answer that pleases us both.

I'll await your response before starting if you have other parameters you would like added to the test scenario I may have overlooked.

testuser you're being too modest. You have an excellent brain for this. It would only take little effort to read through RFC959 to get up to speed. Your input is always welcome.

[REngels]

Klink,

I think that is a fine way to go, but the only FTP problems I have is when I go out to the Internet. I don't have a firewall per se, but a DSL/Ethernet/Wireless Bridge/ Router, that does NAT. It is the NetGear MR314 for reference.

I have done extensive testing using the LAN Sniffer here. As previously noted, there are no problems when using FTP on the local LAN - since all machines can accept the 1514 byte Ethernet Frames.

The problem only occurs when going out to the Internet. Simply, the other Windows and OS9.x machines use an Ethernet packet size of 1454. For some reason the OSX machine still sends Ethernet packets of length 1514 - too big to be sent on the PPPoE WAN connection.

Robert

[Klink]

Rob at this point you seem to be very close to a solution or at the least on the right track. It's clear to me any results of my proposed test wouldn't shed any light on your situation.
Your thread "MTU size - Big problem" raises further interesting needed research on my part. Unfortunately I lack a proper analyzer for Ethernet framing or a PPPoE connection which makes things a tad more difficult. I'll try reading up on TCP/IP transmissions and see if something comes to light.