FTP connection issues, things that make you go humm

[Percula]

Things that make you go humm...

The last few days I have had fits maintaining a connection to FTP. Most of the time I can not connect at all, so I write it off as a continuation of the problems from earlier in the week.

Well tonight, I just can't take it anymore. Yep a little digging and sure enough my firewall is blocking the traffic. Why you might ask? Because of some nasty TCP errors. I am seeing a ton of dup acks and out of orders. From the pcap it almost looks like it is trying to retransmit even though there doesn't seem to be any packet loss.

So I see the start of a classic three way hand shake for the SSL connection...

Me > SYN
FTP > SYN ACK
ME > ACK
ME > ACK (dup)
ME > ACK (dup)
ME > Out of Order
FTP > FIN ACK
ME > ACK
ME > ACK (dup)

And it just goes on with dups and out of orders.

So now I have to crank down my IPS function to allow this crap flow to connect and stay connected.

BTW this is with the beta and the production versions of the client.

Anyone got any ideas?

BTW II, No I did not email support, $10 says no one there wouldn't have a clue about what I was talking about...

[LuckyTxGuy]

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BTW II, No I did not email support, $10 says no one there wouldn't have a clue about what I was talking about...

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I won't take that bet!!! [img]/images/graemlins/grin.gif[/img] $10 says very few people here will completely understand what you're talking about.....including me!lol I get the idea but I honestly know very little about the subject at hand. Good luck!

[nuclear500]

Are the packets being heavily fragmented? Garbled in anyway? You have tried using Ethereal to inspect the packets themselves to see if you can make sense of the actual traffic?

Have you tried watching the SSL traffic like this with another Poker sites client, or even just an SSL website? If you see the same problems with other SSL things - I'd consider making sure you are Windows Update'd as I know that a number of the updates in the last year dealt with the SChannel.dll.

You may want to even consider completely reinstalling the TCP/IP stack, perhaps even look at the LSP list see if anything funky has stuck itself in the TCP/IP stack (using LSPFix http://cexx.org/lspfix.htm)

As the other guy said, there are going to be very few people here who understand what you're saying, let alone get what a TCP handshake consists of (not necessarily just SSL) [img]/images/graemlins/smile.gif[/img]

Hope I've given you some thoughts and ideas, this does perplex me too what could be causing this.

[Percula]

I used Wireshark to do the pcap, and yes I have checked/compared other SSL traffic, and it is normal as one would expect.

It's just the FTP SSL traffic. Even the side FTP HTTP traffic is fine that they use to populate the graphics in the client are fine, it's just the SSL client traffic.

I am 99.9% sure it is not the OS. I did several captures back a couple of months ago when people were having fits with timeouts to FTP, and my traffic was normal back then. It has only been since the last couple of updates that I am seeing this.

[ QUOTE ]
I won't take that bet!!! $10 says very few people here will completely understand what you're talking about.....including me!lol I get the idea but I honestly know very little about the subject at hand. Good luck!

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And I can't take bet either, LOL! But I can hold out hope.

[UbinTook]

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You may want to even consider completely reinstalling the TCP/IP stack, perhaps even look at the LSP list see if anything funky has stuck itself in the TCP/IP stack (using LSPFix http://cexx.org/lspfix.htm)


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That link is dead

[nuclear500]

The forum software is including the ) in the link. Remove it and the link works.