V 6.52 - FTP Problems

[ghisler(Author)]

2JackFoo
This is probably a different problem, and has nothing to do with Serv-U: If the transfer takes a long time (more than 15 minutes normally), a gateway/firewall/nat router etc. may drop the control connection (which is used to send commands like LIST), so TC will wait for ever for the "transfer complete" message from the server.

2josver
Can you create a test ftp account for me, so I can try to reproduce the problem myself? Perhaps there is a bug in Serv-U 5 which causes it to send some invalid data, which hangs both TC and FileZilla.

If your server has Cpanel for management, you can create an account very easily via FTP manager - create account. You can even set a low quota value to avoid abuse of the account. If you would like to do this, then please send me the password by e-mail to support at ghisler dot com (do not post it here!). Thanks for your help.

[JackFoo]

Would this also happen if I selected to send NOOP command every x seconds? Logically it shouldn't...

Thanks.

[ghisler(Author)]

Well, normally you can't send any commands DURING a download/upload, only between while there are no transfers. The NOOP command should prevent the server from disconnecting you - it doesn't disconnect you while a transfer is going on (at least those servers I know), but the gateway/NAT router may!

[JackFoo]

Hmm, I'm confused, there is a control connection and the data connection (during transfers) so router/firewall/whatever will close the control connection if there is no traffic on it (I guess, as it prolly thinks it's useless) but if you send NOOP command every X seconds it's not useless and router/whatever shouldn't touch it.

Well, normally you can't send any commands DURING a download/upload, only between while there are no transfers.[...]

Erm, why, there are two connections exactly for that purpose: to be able to send commands during data transmission.

Thanks.

[ghisler(Author)]

Many FTP servers do not accept any commands on the control connection during a transfer, and may hang or even drop the connection if they receive something.

[JackFoo]

Oh, you mean they implement the FTP protocol badly.. hmm

Thanks.

[josver]

I just installled TC 6.53, in the hope it would solve my problem. I still think it must be a coding error in TC, since no other FTP client seems to have this problem.

(to recap, since the subject got diluted: SERVU as FTP server TC as client, hangs after some initial commands)
This may be a list type problem, since this is what happened :

On first connecting with the new version to the server I got a box where the list format had to be defined. TC apparently did not recognise it.

I saved the format under a name, and could, for one time only, successfully connect.

After disconnecting and trying again, it hung at the same place as before.

Hope this helps

Jos

[ghisler(Author)]

Can you give me access to such a server, please? If yes, please send me the login data by e-mail. Please also send me the definition string you used for this server.

[Zith]

http://rhinosoft.com/Knowledgebase/KBArticle.asp?RefNo=1555&prod=su

An option to disable the FEAT command would be nice, both in ServU and Tcmndr...

[us]

Was this issue ever resolved?

I experience the described problem when connecting to a Serv-U ver. 6.1 server.

I can provide a test-account, if you need to test the behavior.

Regards and happy new year

[ghisler(Author)]

To prevent TC from sending the FEAT command, please add the line
PreventFEAT=1
to wcx_ftp.ini section [General]

From the help:
PreventFEAT=0
1: Do not send the FEAT (supported features) command to servers. Some proxies seem to hang when this command is being sent.